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Probability, STD2 S2 2018 HSC 9 MC

An experiment has three distinct outcomes, A, B and C.

Outcome A occurs 50% of the time. Outcome B occurs 23% of the time.

What is the expected number of times outcome C would occur if the experiment is conducted 500 times?

  1. 115
  2. 135
  3. 250
  4. 365
Show Answers Only

`text(B)`

Show Worked Solution

`text(Expectation of outcome)\ C`

`= 1 – 0.5 – 0.23`

`= 0.27`
 

`:.\ text(Expected times)\ C\ text(occurs)`

`= 0.27 xx 500`

`= 135`

`=>\ text(B)`

Filed Under: Fundamental Understanding (Std 1), Fundamental Understanding (Std 2), Probability Tagged With: Band 3, num-title-ct-core, num-title-qs-hsc, smc-4225-35-Relative frequency

Algebra, STD2 A4 2018 HSC 4 MC

Which graph best represents the equation  `y = x^2-2`?
 

A. B.
C. D.
Show Answers Only

`A`

Show Worked Solution

`y = x^2-2`

`ytext(-intercept) = -2\ \ \ (text(when) = 0)`

`text(Quadratic is positive with vertex at)\ \ y = -2`

`=>A`

Filed Under: Non-Linear: Exponential/Quadratics (Std 2), Quadratics Tagged With: Band 3, num-title-ct-corea, num-title-qs-hsc, smc-4443-10-Identify graphs, smc-830-10-Identify Graphs

Statistics, STD2 S1 2018 HSC 3 MC

A survey asked the following question.

'How many brothers do you have?'

How would the responses be classified?

  1. Categorical, ordinal
  2. Categorical, nominal
  3. Numerical, discrete
  4. Numerical, continuous
Show Answers Only

`text(C)`

Show Worked Solution

`text(The number of brothers a person has is)`

`text(an exact whole number.)`

`:.\ text(Classification is numerical, discrete.)`

`=>\ text(C)`

Filed Under: Classifying Data, Classifying Data (Std 1), Classifying Data (Std 2), Classifying Data (Y12), Data Classification, Investigation and Sampling Methods (Std2-2027) Tagged With: Band 4, common-content, num-title-ct-core, num-title-qs-hsc, smc-1127-20-Classifying Data, smc-5075-15-Numerical, smc-6309-20-Data Classification, smc-820-20-Classifying Data

Plane Geometry, EXT1 2018 HSC 11d

Two secants from the point `C` intersect a circle as shown in the diagram.
 

 
What is the value of `x`?  (2 marks)

--- 4 WORK AREA LINES (style=lined) ---

Show Answers Only

`4`

Show Worked Solution

`text(Using formula for intercepts of intersecting secants:)`

`x (x + 2)` `= 3 (3 + 5)`
`x^2 + 2x` `= 24`
`x^2 + 2x – 24` `= 0`
`(x + 6) (x – 4)` `= 0`
`:. x` `= 4 \ \ \ (x > 0)`

Filed Under: 2. Plane Geometry EXT1, Circle Geometry Tagged With: Band 4, num-title-ct-patha, num-title-qs-hsc, smc-4240-55-Secants

Functions, EXT1 F2 2018 HSC 11a

Consider the polynomial  `P(x) = x^3-2x^2-5x + 6`.

  1. Show that  `x = 1`  is a zero of  `P(x)`.  (1 mark)

    --- 2 WORK AREA LINES (style=lined) ---

  2. Find the other zeros.  (2 marks)

    --- 5 WORK AREA LINES (style=lined) ---

Show Answers Only
  1. `text(See Worked Solution)`
  2. `x = -2 and x = 3`
Show Worked Solution

i.   `P(1) = 1-2-5 + 6 = 0`

`:. x=1\ \ text(is a zero)`

 

ii.   `text{Using part (i)} \ => (x-1)\ text{is a factor of}\ P(x)`

`P(x) = (x-1)*Q(x)`
 

`text(By long division:)`

`P(x)` `= (x-1) (x^2-x-6)`
  `= (x-1) (x-3) (x + 2)`

 
`:.\ text(Other zeroes are:)`

`x = -2 and x = 3`

Filed Under: Polynomials, Remainder and Factor Theorems (Ext1), Roots, Remainders and Factors Tagged With: Band 1, Band 3, num-title-ct-patha, num-title-qs-hsc, smc-1031-10-Factor Theorem, smc-4242-10-Factor Theorem

Measurement, STD2 M1 2017 HSC 30e

A solid is made up of a sphere sitting partially inside a cone.

The sphere, centre `O`, has a radius of 4 cm and sits 2 cm inside the cone. The solid has a total height of 15 cm. The solid and its cross-section are shown.
 


 

Using the formula  `V=1/3 pi r^2h`  where `r`  is the radius of the cone's circular base and `h` is the perpendicular height of the cone, find the volume of the cone, correct to the nearest cm³?  (3 marks)

--- 6 WORK AREA LINES (style=lined) ---

Show Answers Only

`113\ text{cm}^3`

Show Worked Solution

`V = 1/3 xx text(base of cone × height)`

`text(Consider the circular base area of the cone,)`

`text(Find)\ x\ \ text{(using Pythagoras):}`

`x^2` `= 4^2-2^2 = 16-4 = 12`
`x` `= sqrt12\ text(cm)`

 

`:. V` `= 1/3 xx pi xx (sqrt12)^2 xx (15-6)`
  `= 1/3 xx pi xx 12 xx 9`
  `= 113.097…`
  `= 113\ text{cm}^3\ text{(nearest cm}^3 text{)}`

Filed Under: Perimeter, Area and Volume (Std 2), Volume, Volume, Mass and Capacity (Std2-2027) Tagged With: Band 6, num-title-ct-extension, num-title-qs-hsc, smc-4235-50-Pyramids/Cones, smc-4235-60-Spheres, smc-6304-50-Volume (Circular Measure), smc-798-50-Volume (Circular Measure)

Plane Geometry, 2UA 2017 HSC 15a

The triangle `ABC` is isosceles with  `AB = AC`  and the size of `/_BAC` is `x^@`.

Points `D` and `E` are chosen so that `Delta ABC, Delta ACD` and `Delta ADE` are congruent, as shown in the diagram.
 

Find the value of `x` for which `AB` is parallel to `ED`, giving reasons.  (3 marks)

--- 6 WORK AREA LINES (style=lined) ---

Show Answers Only

`x = 36`

Show Worked Solution

`text(All base angles) = 1/2(180-x)\ \ text{(Angle sum of}\ Delta text{)}`

`text(If)\ \ AB\ text(||)\ ED,`

`/_ BAD` `= /_ ADE\ \ \ text{(alternate angles)}`
`2x` `= 1/2 (180-x)`
`4x` `= 180-x`
`5x` `= 180`
`x` `= 36^{\circ}`

Filed Under: 2. Plane Geometry, Congruency Tagged With: Band 4, num-title-ct-pathc, num-title-qs-hsc, smc-4747-50-Other problems

Functions, EXT1 F2 2017 HSC 1 MC

Which polynomial is a factor of  `x^3-5x^2 + 11x-10`?

  1. `x-2`
  2. `x + 2`
  3. `11x-10`
  4. `x^2-5x + 11`
Show Answers Only

`A`

Show Worked Solution
`f(2)` `= 2^3-5*2^2 + 11*2-10`
  `= 8-20 + 22 – 10`
  `= 0`

 
`:. (x-2)\ text(is a factor)`

`⇒ A`

Filed Under: Polynomials, Remainder and Factor Theorems (Ext1), Roots, Remainders and Factors Tagged With: Band 2, num-title-ct-patha, num-title-qs-hsc, smc-1031-10-Factor Theorem

Functions, 2ADV F1 2017 HSC 11h

Find the domain of the function  `f(x) = sqrt (3-x)`.  (2 marks)

Show Answers Only

`x <= 3 or (-oo,3].`

Show Worked Solution

`text(Domain of)\ \ f(x) = sqrt (3-x)`

`3-x` `>= 0`
`x` `<= 3`

 

`text(Note domain can also be expressed as:)\ \ (-oo,3]`

Filed Under: 4. Real Functions, Functions and Other Graphs, Further Functions and Relations (Y11), Other Functions and Relations (Adv-2027) Tagged With: Band 4, num-title-ct-patha, num-title-qs-hsc, smc-4244-10-Domain, smc-4244-70-Square root, smc-6216-40-Square-Root Functions, smc-6218-40-Square-Root Functions, smc-987-40-Square-Root Functions

Functions, EXT1* F1 2017 HSC 8 MC

The region enclosed by  `y = 4 - x,\ \ y = x`  and  `y = 2x + 1`  is shaded in the diagram below.
 

Which of the following defines the shaded region?

A.   `y <= 2x + 1, qquad` `y <= 4-x, qquad` `y >= x`
B.   `y >= 2x + 1, qquad` `y <= 4-x, qquad` `y >= x`
C.   `y <= 2x + 1, qquad` `y >= 4-x, qquad` `y >= x`
D.   `y >= 2x + 1, qquad` `y >= 4-x, qquad` `y >= x`
Show Answers Only

`A`

Show Worked Solution

`text(Consider)\ \ y = 2x + 1,`

`text(Shading is below graph)`

`=> y <= 2x + 1`

`text(Consider)\ \ y = 4-x,`

`text(Shading is below graph)`

`=> y <= 4-x`

`=>  A`

Filed Under: 4. Real Functions, Functions and Other Graphs, Inequalities (Ext1) Tagged With: Band 4, num-title-ct-patha, num-title-qs-hsc, smc-1033-40-Regions, smc-4244-80-Linear inequalities

Functions, 2ADV F1 2017 HSC 2 MC

Which expression is equal to  `3x^2-x-2`?

  1. `(3x-1) (x + 2)`
  2. `(3x + 1) (x-2)`
  3. `(3x-2) (x + 1)`
  4. `(3x + 2) (x-1)`
Show Answers Only

`D`

Show Worked Solution

`3x^2-x-2= (3x + 2) (x-1)`

`=>  D`

Filed Under: Factors and Other Equations, Quadratics and Cubic Functions (Adv-2027), Quadratics and Cubic Functions (Y11), Quadratics and Cubics Tagged With: Band 3, num-title-ct-pathc, num-title-qs-hsc, smc-4386-35-Quadratics (Non-monic), smc-6215-10-Quadratics, smc-6215-40-Factorise, smc-984-10-Quadratics

Functions, 2ADV F1 2017 HSC 1 MC

What is the gradient of the line  `2x + 3y + 4 = 0`?

  1. `-2/3`
  2. `2/3`
  3. `-3/2`
  4. `3/2`
Show Answers Only

`A`

Show Worked Solution
`2x + 3y + 4` `= 0`
`3y` `= -2x-4`
`y` `= -2/3 x-4/3`
`:.\ text(Gradient)` `= -2/3`

 
`=>  A`

Filed Under: 6. Linear Functions, Cartesian Plane, Linear Equations and Basic Graphs (Std 2), Linear Functions (Adv-2027), Linear Functions (Y11) Tagged With: Band 3, common-content, num-title-ct-pathc, num-title-qs-hsc, smc-4422-20-Gradient, smc-4422-50-General form, smc-6214-05-Coordinate Geometry, smc-792-10-Gradient, smc-985-30-Coordinate Geometry

Algebra, STD2 A4 2017 HSC 28e

A movie theatre has 200 seats. Each ticket currently costs $8.

The theatre owners are currently selling all 200 tickets for each session. They decide to increase the price of tickets to see if they can increase the income earned from each movie session.

It is assumed that for each one dollar increase in ticket price, there will be 10 fewer tickets sold.

A graph showing the relationship between an increase in ticket price and the income is shown below.
 


 

  1. What ticket price should be charged to maximise the income from a movie session?  (1 mark)

    --- 1 WORK AREA LINES (style=lined) ---

  2. What is the number of tickets sold when the income is maximised?  (1 mark)

    --- 1 WORK AREA LINES (style=lined) ---

  3. The cost to the theatre owners of running each session is $500 plus $2 per ticket sold.

     

    Calculate the profit earned by the theatre owners when the income earned from a session is maximised.  (2 marks)

    --- 4 WORK AREA LINES (style=lined) ---

Show Answers Only
  1. `$14`
  2. `140`
  3. `$1180`
Show Worked Solution

i.   `text(Graph is highest when increase = $6)`

♦ Mean mark 50%.

`:.\ text(Ticket price)\ = 8 + 6= $14`
 

ii.   `text(Solution 1)`

♦ Mean mark 45%.

`text(Tickets sold)\ =200-(4 xx 10)=140`
 

`text(Solution 2)`

`text(Tickets)\ = text(max income)/text(ticket price) = 1960/14= 140`
 

iii.  `text{Cost}\ = 140 xx $2 + $500= $780`

`:.\ text(Profit when income is maximised)`

`= 1960-780`

`= $1180`

Filed Under: Exponential/Quadratic (Projectile), Non-Linear: Exponential/Quadratics (Std 2) Tagged With: Band 4, Band 5, num-title-ct-coreb, num-title-qs-hsc, smc-4443-70-Other applications, smc-830-20-Quadratics

Statistics, STD2 S1 2017 HSC 27a

Jamal surveyed eight households in his street. He asked them how many kilolitres (kL) of water they used in the last year. Here are the results.

`220, 105, 101, 450, 37, 338, 151, 205`

  1. Calculate the mean of this set of data.  (1 mark)

    --- 1 WORK AREA LINES (style=lined) ---

  2. What is the standard deviation of this set of data, correct to one decimal place?  (1 mark)

    --- 1 WORK AREA LINES (style=lined) ---

Show Answers Only
  1. `200.875`
  2. `127.4\ \ text{(1 d.p.)}`
Show Worked Solution
a.   `text(Mean)` `= (220 + 105 + 101 + 450 + 37 + 338 + 151 + 205) ÷ 8`
    `= 200.875`
♦ Mean mark part (ii) 47%.
IMPORTANT: The population standard deviation is required here.

 

b.   `text(Std Dev)` `= 127.357…\ \ text{(by calc)}`
    `= 127.4\ \ text{(1 d.p.)}`

Filed Under: Measures of Centre and Spread (Std2-2027), Standard Deviation, Summary Statistics - No Graph (Std 2), Summary Statistics - No graph (Y12), Summary Statistics (no graph), Summary Statistics (Std 1) Tagged With: Band 3, Band 5, common-content, num-title-ct-corea, num-title-qs-hsc, smc-1131-10-Mean, smc-1131-50-Std Dev (by calc), smc-5020-10-By calculator, smc-6312-10-Mean, smc-6312-50-Std Dev (by Calc), smc-824-10-Mean, smc-824-50-Std Dev (by calc), smc-999-50-Std Dev (by calc)

Measurement, STD2 M6 2017 HSC 26d

A sewer pipe needs to be placed into the ground so that it has a 2° angle of depression. The length of the pipe is 15 000 mm.
 


 

How much deeper should one end of the pipe be compared to the other end? Answer to the nearest mm.  (2 marks)

--- 4 WORK AREA LINES (style=lined) ---

Show Answers Only

`523\ text{mm  (nearest mm)}`

Show Worked Solution

`text(Let)\ \ x = text(depth needed)`

`sin 2^@` `= x/(15\ 000)`
`x` `= 15\ 000 xx sin 2^@`
  `= 523.49…`
  `= 523\ text{mm  (nearest mm)}`

Filed Under: M3 Right-Angled Triangles (Y12), Pythagoras and basic trigonometry, Pythagoras and Right-Angled Trig (Std2), Right-Angled Trig Tagged With: Band 4, num-title-ct-coreb, num-title-qs-hsc, smc-1103-20-Right-angled Trig, smc-4552-40-Real world applications, smc-4552-50-Angle of depression, smc-802-20-Right-Angled Trig

Measurement, STD2 M1 2017 HSC 25 MC

In the circle, centre `O`, the area of the quadrant is 100 cm².
 


 

What is the arc length `l`, correct to one decimal place?

  1. 8.9 cm
  2. 11.3 cm
  3. 17.7 cm
  4. 25.1 cm
Show Answers Only

`C`

Show Worked Solution

`text(Find)\ r:`

♦ Mean mark 44%.
`text(Area)` `= 1/4 pir^2`
`100` `= 1/4 pir^2`
`r^2` `= 400/pi`
`:. r` `= 11.283…\ text(cm)`

 

`text(Arc length)` `= theta/360 xx 2pir`
  `= 90/360 xx 2pi xx 11.283…`
  `= 17.724…`
  `= 17.7\ text(cm)`

 
`=> C`

Filed Under: Area and Surface Area, MM6 - Spherical Geometry, Perimeter and Area (Std 1), Perimeter and Area (Std2-2027), Perimeter, Area and Volume (Std 2) Tagged With: Band 5, num-title-ct-corea, num-title-qs-hsc, smc-1121-20-Perimeter and Area (Circular Measure), smc-4234-20-Area (circular), smc-6483-50-Area (Circular Measure), smc-798-20-Perimeter and Area (Circular Measure)

Probability, STD2 S2 2017 HSC 15 MC

The faces on a twenty-sided die are labelled  $0.05, $0.10, $0.15, … , $1.00.

The die is rolled once.

What is the probability that the amount showing on the upper face is more than 50 cents but less than 80 cents?

A.     `1/4`

B.     `3/10`

C.     `7/20`

D.     `1/2`

Show Answers Only

`A`

Show Worked Solution

`text(Possible faces that satisfy are:)`

♦ Mean mark 50%.

`55text(c),60text(c),65text(c),70text(c),75text(c)`

`:.\ text(Probability)` `= 5/20`
  `= 1/4`

`=>A`

Filed Under: Combinations and Single Stage Events (Std 2), Probability, Single and Multi-Stage Events (Std 1), Single stage events Tagged With: Band 5, num-title-ct-core, num-title-qs-hsc, smc-1135-05-Simple Probability, smc-4225-15-Single-stage events, smc-828-10-Simple Probability

Statistics, STD2 S4 2017 HSC 12 MC

Which of the data sets graphed below has the largest positive correlation coefficient value?
 

A.      B.     
C.      D.     
Show Answers Only

\(C\)

Show Worked Solution

\(\text{Largest positive correlation occurs when both variables move}\)

\(\text{in tandem. The tighter the linear relationship, the higher the}\)

\(\text{correlation.}\)

\(\Rightarrow C\)

\(\text{(Note that B is negatively correlated)}\)

Filed Under: Bivariate Data, Bivariate Data Analysis (Y12), Correlation / Body Measurements, S3 Further Statistical Analysis (Y12), S4 Bivariate Data Analysis (Y12) Tagged With: Band 3, common-content, num-title-ct-coreb, num-title-qs-hsc, smc-1001-30-Correlation, smc-1113-30-Correlation, smc-5022-30-Correlation, smc-785-30-Correlation

Financial Maths, STD2 F1 2017 HSC 11 MC

A new car was bought for $19 900 and one year later its value had depreciated to $16 300.

What is the approximate depreciation, expressed as a percentage of the purchase price?

  1. 18%
  2. 22%
  3. 78%
  4. 82%
Show Answers Only

`A`

Show Worked Solution
`text(Net Depreciation)` `= 19\ 900-16\ 300`
  `= $3600`

 

`:. %\ text(Depreciation)` `= 3600/(19\ 900) xx 100`
  `= 18.09…text(%)`

`=>A`

Filed Under: Depreciation, Depreciation - Declining Balance (Std 2), Depreciation / Running costs, Simple Interest and S/L Depreciation (Std 1), Simple Interest and S/L Depreciation (Std 2) Tagged With: Band 4, num-title-ct-coreb, num-title-qs-hsc, smc-1124-20-Straight Line Depreciation, smc-808-20-Straight Line Depreciation, smc-813-20-Find r

Algebra, STD2 A1 2017 HSC 9 MC

What is the value of  `x`  in the equation  `(5-x)/3 = 6`?

  1. `-13`
  2. `-3`
  3. `3`
  4. `13`
Show Answers Only

`A`

Show Worked Solution
`(5-x)/3` `= 6`
`5-x` `= 18`
`x` `= 5-18`
  `= -13`

`=>A`

Filed Under: Algebraic Fractions, Linear and Other Equations, Substitution and Other Equations (Std 1), Substitution and Other Equations (Std 2), Substitution and Other Equations (Std2-2027) Tagged With: Band 3, common-content, num-title-ct-corea, num-title-qs-hsc, smc-1116-30-Algebraic Fractions, smc-4402-10-Single fraction, smc-6234-30-Algebraic Fractions, smc-789-30-Algebraic Fractions

Financial Maths, STD2 F1 2017 HSC 6 MC

Tom earns a weekly wage of $1025. He also receives an additional allowance of $87.50 per day when handling toxic substances.

What is Tom’s income in a fortnight in which he handles toxic substances on 5 separate days?

  1. $1112.50
  2. $1462.50
  3. $2225.00
  4. $2487.50
Show Answers Only

`D`

Show Worked Solution
`text(Fortnightly wage)` `= 2 xx 1025`
  `= $2050`
`text(Allowances)` `= 5 xx 87.50`
  `= $437.50`

 

`:.\ text(Income)` `= 2050 + 437.50`
  `= $2487.50`

 
`=>D`

Filed Under: Earning and Spending Money, Earning Money and Budgeting (Std 1), Earning Money and Budgeting (Std 2), FM1 - Earning money, Ways of Earning (Std2-2027) Tagged With: Band 3, num-title-ct-corea, num-title-qs-hsc, smc-1126-10-Wages, smc-4331-10-Wages, smc-6276-10-Wages/Salaries, smc-810-10-Wages

Probability, STD2 S2 2017 HSC 5 MC

In a survey of 200 randomly selected Year 12 students it was found that 180 use social media.

Based on this survey, approximately how many of 75 000 Year 12 students would be expected to use social media?

A.     60 000

B.     67 500

C.     74 980

D.     75 000

Show Answers Only

`B`

Show Worked Solution
`text(Expected number)` `= 180/200 xx 75\ 000`
  `= 67\ 500`

`=> B`

Filed Under: DS5/6 - Normal Distribution and Sampling, Probability, Relative Frequency, Relative Frequency (Std 1), Relative Frequency (Std 2), Relative Frequency (Y11) Tagged With: Band 3, common-content, num-title-ct-core, num-title-qs-hsc, smc-1133-10-Surveys/Two-Way Tables, smc-1133-30-Expected Frequency (np), smc-4225-35-Relative frequency, smc-827-10-Surveys/Two-Way Tables, smc-827-40-Expected Frequency (np), smc-990-10-Surveys/Two-Way Tables, smc-990-40-Expected Frequency (np)

Algebra, STD2 A2 2017 HSC 3 MC

The graph shows the relationship between infant mortality rate (deaths per 1000 live births) and life expectancy at birth (in years) for different countries.
 

What is the life expectancy at birth in a country which has an infant mortality rate of 60?

  1. 68 years
  2. 69 years
  3. 86 years
  4. 88 years
Show Answers Only

\(A\)

Show Worked Solution

\(\text{When infant mortality rate is 60, life expectancy}\)

\(\text{at birth is 68 years (see below).}\)
 

\(\Rightarrow A\)

Filed Under: Applications: Currency, Fuel and Other Problems (Std 1), Applications: Currency, Fuel and Other Problems (Std 2), Applications: Fuel and Other Problems (Std2-2027), Bivariate Data, Life Expectancy, Linear Applications, S3 Further Statistical Analysis (Y12), S4 Bivariate Data Analysis (Y12) Tagged With: Band 3, common-content, num-title-ct-coreb, num-title-qs-hsc, smc-1001-10-Line of Best Fit, smc-1113-10-Line of Best Fit, smc-1119-30-Other Linear Applications, smc-5022-10-Line of best fit graphs, smc-6256-30-Other Linear Applications, smc-785-10-Line of Best Fit, smc-793-30-Other Linear Applications

Statistics, STD2 S1 2017 HSC 1 MC

The box-and-whisker plot for a set of data is shown.
 

What is the median of this set of data?

  1. 15
  2. 20
  3. 30
  4. 35
Show Answers Only

`C`

Show Worked Solution

`text(Median = 30)`

`=> C`

Filed Under: Box Plots and 5-Number Summary, Stem & Leaf, Box & Whisker, Summary Statistics - Box Plots (Std 2), Summary Statistics - Box Plots (Std2-2027), Summary Statistics (Std 1) Tagged With: Band 2, common-content, num-title-ct-corea, num-title-qs-hsc, smc-1131-35-Box Plots, smc-5021-18-Find median, smc-5021-50-Box plot (single), smc-6313-10-Single Box Plots, smc-825-10-Single Box-Plots

Plane Geometry, EXT1 2016 HSC 4 MC

In the diagram, `O` is the centre of the circle `ABC`, `D` is the midpoint of `BC`, `AT` is the tangent at `A` and  `∠ATB = 40^@`.
 

What is the size of the reflex angle `DOA`?

  1. `80^@`
  2. `140^@`
  3. `220^@`
  4. `280^@`
Show Answers Only

`C`

Show Worked Solution

 

`/_ ODT` `=90^@\ \ text{(line through centre bisecting chord)}`
`/_OAT` `= 90^@\ \ text{(tangent ⊥ to radius at point of contact)}`
`/_ DOA` `= 360-(90 + 90 + 40)`
  `= 140^@`

 

`:. DOA\ \ text{(reflex)}` `= 360-140`
  `= 220^@`

`=>   C`

Filed Under: 2. Plane Geometry EXT1, Circle Geometry Tagged With: Band 4, num-title-ct-path, num-title-qs-hsc, smc-4240-50-Chord properties, smc-4240-60-Tangents

Functions, EXT1 F2 2016 HSC 2 MC

What is the remainder when  `2x^3-10x^2 + 6x + 2`  is divided by  `x-2`?

  1. `-66`
  2. `-10`
  3. `-x^3 + 5x^2-3x-1`
  4. `x^3-5x^2 + 3x + 1`
Show Answers Only

`B`

Show Worked Solution
`P(2)` `= 2 · 2^3-10 · 2^2 + 6 · 2 + 2`
  `= -10`

 
`=>   B`

Filed Under: Polynomials, Remainder and Factor Theorems (Ext1), Roots, Remainders and Factors Tagged With: Band 2, num-title-ct-patha, num-title-qs-hsc, smc-1031-20-Remainder Theorem, smc-4242-10-Factor Theorem

L&E, 2ADV E1 2016 HSC 14e

Write  `log 2 + log 4 + log 8 + … + log 512`  in the form  `a log b`  where `a` and `b` are integers greater than `1.`  (2 marks)

--- 5 WORK AREA LINES (style=lined) ---

Show Answers Only

`45 log 2`

Show Worked Solution

`log 2 + log 4 + log 8 + … + log 512`

`= log 2^1 + log 2^2 + log2^3 + … + log 2^9`

`= log 2 + 2 log 2 + 3 log 2 + … + 9 log 2`

`= 45 log 2`

♦ Mean mark 40%.
 
TIP: Note that `log 2 = log_10 2`

Filed Under: Log/Index Laws and Equations (Adv-2027), Log/Index Laws and Equations (Y11), Log/Index laws and Other Equations, Logarithms Tagged With: Band 5, num-title-ct-patha, num-title-qs-hsc, smc-4243-30-Power rule, smc-6455-20-Logs - Power Rule, smc-963-20-Log - power rule

Measurement, STD2 M1 2016 HSC 30c

A school playground consists of part of a circle, with centre `O`, and a rectangle as shown in the diagram. The radius `OB` of the circle is 45 m, the width `BC` of the rectangle is 20 m and `AOB` is 100°.
 

What is the area of the whole playground, correct to the nearest square metre?  (5 marks)

--- 12 WORK AREA LINES (style=lined) ---

Show Answers Only

`6971\ text{m²  (nearest m²)}`

Show Worked Solution

`text(In)\ DeltaOEB,`

`sin50^@` `= (EB)/45`
`EB` `= 45 xx sin50^@`
  `= 34.47…`
`:. AB` `= 2 xx 34.47…`
  `= 68.944\ \ (text(3 d.p.))`

 

`cos50^@` `= (OE)/45`
`:. OE` `= 45 xx cos50^@`
  `= 28.925\ \ (text(3 d.p.))`

 

`text(Area of)\ DeltaOAB`

`= 1/2 xx AB xx OE`

`= 1/2 xx 68.944 xx 28.925`

`= 997.12\ text(m²)`

 

`text(Area)\ ABCD` `= 20 xx 68.944`
  `= 1378.88\ text(m²)`

 

`text(Area of major sector)\ OAB`

`= pi xx 45^2 xx 260/360`

`= 4594.58\ text(m²)`

 

`:.\ text(Area of playground)`

`= 997.12 + 1378.88 + 4594.58`

`= 6970.58`

`= 6971\ text{m²  (nearest m²)}`

Filed Under: 2-Triangle and Harder Examples, Area and Surface Area, Areas and Volumes (Harder), MM6 - Spherical Geometry, Perimeter and Area (Std2-2027), Perimeter, Area and Volume (Std 2) Tagged With: Band 4, num-title-ct-extension, num-title-qs-hsc, smc-6483-50-Area (Circular Measure), smc-798-20-Perimeter and Area (Circular Measure)

Measurement, STD2 M1 2016 HSC 28e

A company makes large marshmallows. They are in the shape of a cylinder with diameter 5 cm and height 3 cm, as shown in the diagram.

2ug-2016-hsc-q28_4

  1. Find the volume of one of these large marshmallows, correct to one decimal place.  (2 marks)

    --- 4 WORK AREA LINES (style=lined) ---

A cake is to be made by stacking 24 of these large marshmallows and filling the gaps between them with chocolate. The diagrams show the cake and its top view. The shading shows the gaps to be filled with chocolate.
 

2ug-2016-hsc-q28_5

  1. What volume of chocolate will be required? Give your answer correct to the nearest whole number.  (3 marks)

    --- 6 WORK AREA LINES (style=lined) ---

Show Answers Only
  1. `58.9\ text{cm}^3`
  2. `193\ text{cm}^3`
Show Worked Solution
a.    `V` `= pir^2h`
    `= pi xx 2.5^2 xx 3`
    `= 58.904…`
    `= 58.9\ text{cm³  (1 d.p.)}`

 

b.    2ug-2016-hsc-q28-answer1

`text(Volume of rectangle)`

♦ Mean mark part (ii) 35%.

`= 15 xx 10 xx 6`

`= 900\ text(cm)^3`
 

`text(Volume of marshmallows in rectangle)`

`= 6 xx 2 xx 58.9`

`= 706.8\ text(cm)^3`

 

`:.\ text(Volume of chocolate)`

`= 900-706.8`

`= 193.2`

`= 193\ text{cm}^3 \ text{(nearest cm}^3 text{)}`

Filed Under: Areas and Volumes (Harder), Perimeter, Area and Volume (Std 2), Volume, Mass and Capacity (Std2-2027) Tagged With: Band 4, Band 5, num-title-ct-corea, num-title-qs-hsc, smc-4235-20-Cylinders, smc-6304-50-Volume (Circular Measure), smc-798-50-Volume (Circular Measure)

Financial Maths, STD2 F1 2016 HSC 26f

Theo is completing his tax return. He has a gross salary of $82 521 and income from a rental property totalling $10 920. He is claiming $13 420 in allowable deductions.

  1. Determine Theo’s taxable income.  (1 mark)

    --- 2 WORK AREA LINES (style=lined) ---

  2. Using the tax table below, calculate Theo’s tax payable.  (2 marks)

\begin{array} {|l|l|}
\hline
\rule{0pt}{2.5ex}\textit{    Taxable income}\rule[-1ex]{0pt}{0pt} & \textit{    Tax payable}\\
\hline
\rule{0pt}{2.5ex}\text{\$0 – \$18 200}\rule[-1ex]{0pt}{0pt} & \text{Nil}\\
\hline
\rule{0pt}{2.5ex}\text{\$18 201 – \$37 000}\rule[-1ex]{0pt}{0pt} & \text{19 cents for each \$1 over \$18 200}\\
\hline
\rule{0pt}{2.5ex}\text{\$37 001 – \$80 000}\rule[-1ex]{0pt}{0pt} & \text{\$3572 plus 32.5 cents for each \$1 over \$37 000}\\
\hline
\rule{0pt}{2.5ex}\text{\$80 001 – \$180 000}\rule[-1ex]{0pt}{0pt} & \text{\$17 547 plus 37 cents for each \$1 over \$80 000}\\
\hline
\rule{0pt}{2.5ex}\text{\$180 001 and over}\rule[-1ex]{0pt}{0pt} & \text{\$54 547 plus 45 cents for each \$1 over \$180 000}\\
\hline
\end{array}

--- 4 WORK AREA LINES (style=lined) ---

  1. In addition to the above tax, Theo must also pay a Medicare levy of $1600.42
  2. Theo has already paid $20 525 as Pay As You Go (PAYG) tax.
  3. Should Theo receive a tax refund or will he owe more tax? Justify your answer with calculations.  (2 marks)

    --- 4 WORK AREA LINES (style=lined) ---

Show Answers Only
  1. `$80\ 021`
  2. `$17\ 554.77`
  3. `$1369.81\ text(refund)`
Show Worked Solution

a.   `text(Taxable income)`

`= 82\ 521 + 10\ 920-13\ 420`

`= $80\ 021`

 

b.   `text(Tax payable)`

`= 17\ 547 + (80\ 021-80\ 000) xx 0.37`

`= $17\ 554.77`

 

c.   `text(Total tax payable)`

`= 17\ 554.77 + 1600.42`

`= $19\ 155.19`
 

`text(Tax paid > tax payable)`

`:.\ text(Refund)` `= 20\ 525-19\ 155.19`
  `= $1369.81`

Filed Under: Earning and Spending Money, FM3 - Taxation, Tax and Percentage Increase/Decrease (Std 1), Tax and Percentage Increase/Decrease (Std 2), Taxation (Std2-2027) Tagged With: Band 4, num-title-ct-corea, num-title-qs-hsc, smc-1125-10-Tax Tables, smc-1125-40-Medicare Levy, smc-4331-50-Tax tables, smc-4331-55-PAYG, smc-6277-10-Tax Tables, smc-6277-20-Medicare Levy, smc-831-10-Tax Tables, smc-831-40-Medicare Levy

Financial Maths, STD2 F1 2016 HSC 26e

Jenny earns a yearly salary of  $63 752. Her annual leave loading is 17.5% of four weeks pay.

Calculate her total pay for her four weeks of annual leave.  (3 marks)

--- 6 WORK AREA LINES (style=lined) ---

Show Answers Only

`$5762.20`

Show Worked Solution

`text(4 weeks’ normal pay)`

`= 4/52 xx 63\ 752`

`= $4904`

 

`:.\ text(Annual leave pay)`

`= 4904(1 + 17.5/100)`

`= $5762.20`

Filed Under: Earning and Spending Money, Earning Money and Budgeting (Std 1), Earning Money and Budgeting (Std 2), FM1 - Earning money, Ways of Earning (Std2-2027) Tagged With: Band 4, num-title-ct-corea, num-title-qs-hsc, smc-1126-10-Wages, smc-4331-10-Wages, smc-4331-30-Leave loading, smc-6276-10-Wages/Salaries, smc-810-10-Wages

Algebra, 2UG 2016 HSC 26b

Simplify  `(8x^4y)/(24x^3y^5)`.  (2 marks)

Show Answers Only

`x/(3y^4)`

Show Worked Solution
`(8x^4y)/(24x^3y^5)` `=(x^((4-3))y^((1-5)))/3`  
  `=(xy^(-4))/3`  
  `=x/(3y^4)`  

Filed Under: Index and Log Laws, Indices Tagged With: Band 4, num-title-ct-pathb, num-title-qs-hsc, smc-4228-10-Positive integers

Measurement, STD2 M1 2016 HSC 26a

Calculate the surface area of a sphere with a radius of 5 cm, correct to the nearest whole number.  (1 mark)
 

--- 3 WORK AREA LINES (style=lined) ---

Show Answers Only

`314\ text{cm²}`

Show Worked Solution
`SA` `= 4pir^2`
  `= 4 xx pi xx 5^2`
  `= 314.15…`
  `= 314\ text{cm²  (nearest cm²)}`

Filed Under: Area and Surface Area, Areas and Volumes (Harder), Perimeter, Area and Volume (Std 2), Surface Area (Std2-2027) Tagged With: Band 2, num-title-ct-pathb, num-title-qs-hsc, smc-4234-50-SA (sphere), smc-6484-20-Surface Area (Circular Measure), smc-798-25-Surface Area

Algebra, STD2 A1 2016 HSC 24 MC

Which of the following correctly expresses `Q` as the subject of  `e = iR + Q/C`?

  1. `Q = Ce + CiR`
  2. `Q = Ce-CiR`
  3. `Q = (e + iR)/C`
  4. `Q = (e-iR)/C`
Show Answers Only

`=> B`

Show Worked Solution
`e` `= iR + Q/C`
`Q/C` `= e-iR`
`:. Q` `= C(e-iR)`
  `= Ce-CiR`

 
`=> B`

Filed Under: Formula Rearrange, Formula Rearrange (Std 1), Formula Rearrange (Std 2), Formula Rearrange (Std2-2027), Linear Tagged With: Band 4, num-title-ct-pathc, num-title-qs-hsc, smc-1200-10-Linear, smc-1201-10-Linear, smc-4362-20-Formula rearrange, smc-6236-10-Linear

Probability, STD2 S2 2016 HSC 23 MC

A group of 485 people was surveyed. The people were asked whether or not they smoke. The results are recorded in the table.
 

A person is selected at random from the group.

What is the approximate probability that the person selected is a smoker OR is male?

  1. 33%
  2. 18%
  3. 68%
  4. 87%
Show Answers Only

`=> C`

Show Worked Solution

`P(text(Smoker or a male))`

`= (text(Total males + female smokers))/(text(Total surveyed))`

`= (264 + 68)/485`

`= 0.684…`
 

`=> C`

♦♦ Mean mark 34%.

Filed Under: Relative Frequency, Relative Frequency (Std 1), Relative Frequency (Std 2), Relative Frequency (Y11), Relative Frequency and Venn Diagrams Tagged With: Band 6, common-content, num-title-ct-pathb, num-title-qs-hsc, smc-1133-10-Surveys/Two-Way Tables, smc-4815-10-2-Way tables, smc-4815-50-Conditional probability, smc-827-10-Surveys/Two-Way Tables, smc-990-10-Surveys/Two-Way Tables

Statistics, STD2 S1 2016 HSC 22 MC

The box-and-whisker plots show the results of a History test and a Geography test.
 

In History, 112 students completed the test. The number of students who scored above 30 marks was the same for the History test and the Geography test.

How many students completed the Geography test?

  1. 8
  2. 50
  3. 56
  4. 112
Show Answers Only

`=> C`

Show Worked Solution

`text{In History} \ => \  text{Q}_3 = 30\ \text{marks}`

`:.\ text{Scoring over 30}\ = 25text(%) xx 112 = 28\ \text{students}`
 

`text{In Geography} \ => \ text{Median}\ = 30\ \text{marks}`

`:.\ text{Students completing Geography}\ =2 xx 28 = 56\ \text{students}`

`=> C`

Filed Under: Box Plots and 5-Number Summary, Stem & Leaf, Box & Whisker, Summary Statistics - Box Plots (Std 2), Summary Statistics - Box Plots (Std2-2027), Summary Statistics - Box Plots (Y12), Summary Statistics (Std 1) Tagged With: Band 4, common-content, num-title-ct-corea, num-title-qs-hsc, smc-1000-20-Parallel Box-Plots, smc-1131-35-Box Plots, smc-5021-60-Box plots (parallel), smc-6313-20-Parallel Box Plots, smc-825-20-Parallel Box-Plots

Financial Maths, STD2 F1 2016 HSC 20 MC

Isabella works a 35-hour week and is paid at an hourly rate of $18. Any overtime hours worked are paid at time-and-a-half. In a particular week, she earned $1008.

How many hours in total did Isabella work in this week to earn this amount?

  1. 37.3
  2. 42
  3. 49
  4. 56
Show Answers Only

`=> C`

Show Worked Solution

`text(Let)\ \ X=\ text(number of extra hours worked.)`

`text(Total wage)` `= 35 xx 18 + X xx 27`
 `1008` `= 630 + 27X`
`27X` `=378`
`X` `=14`

 

`:.\ text(Total hours worked)\ =35+14=49`

`=> C`

Filed Under: Earning and Spending Money, Earning Money and Budgeting (Std 1), Earning Money and Budgeting (Std 2), FM1 - Earning money, Ways of Earning (Std2-2027) Tagged With: Band 4, num-title-ct-corea, num-title-qs-hsc, smc-1126-10-Wages, smc-4331-10-Wages, smc-6276-10-Wages/Salaries, smc-810-10-Wages

Statistics, STD2 S1 2016 HSC 19 MC

A soccer referee wrote down the number of goals scored in 9 different games during the season.

`2,  \ 3,  \ 3,  \ 3,  \ 5,  \ 5,  \ 8,  \ 9,  \ ...`

The last number has been omitted. The range of the data is 10.

What is the five-number summary for this data set?

  1. `2, 3, 5, 8.5, 12`
  2. `2, 3, 5, 8.5, 10`
  3. `2, 3, 5, 8, 12`
  4. `2, 3, 5, 8, 10`
Show Answers Only

`=> A`

Show Worked Solution

`text{Since range is 10} \ => \ text{Last data point = 12}`

`text{Q}_1 = 3`

`text{Q}_3 = (8 + 9)/2 = 8.5`

`text(Median = 5)`

`=> A`

♦ Mean mark 46%.

Filed Under: Box Plots and 5-Number Summary, Measures of Centre and Spread (Std2-2027), Stem & Leaf, Box & Whisker, Summary Statistics - Box Plots (Std 2), Summary Statistics - Box Plots (Std2-2027), Summary Statistics - Box Plots (Y12), Summary Statistics - No Graph (Std 2), Summary Statistics (no graph), Summary Statistics (Std 1) Tagged With: Band 5, common-content, num-title-ct-corea, num-title-qs-hsc, smc-1000-10-Single Box-Plots, smc-5021-15-5 number (even values), smc-5021-18-Find median, smc-5021-25-Find range, smc-6312-70-Other, smc-6313-10-Single Box Plots, smc-824-70-Other, smc-825-10-Single Box-Plots

Measurement, STD2 M7 2016 HSC 16 MC

The width (`W`) of a river can be calculated using two similar triangles, as shown in the diagram.
  

What is the approximate width of the river?

  1. `17.8\ text(m)`
  2. `19.3\ text(m)`
  3. `23.2\ text(m)`
  4. `24.9\ text(m)`
Show Answers Only

`=> A`

Show Worked Solution

`text{Triangles are similar (equiangular)}`

`text(Using similar ratios:)`

`W/(7.1)` `= 20.3/8.1`
`:. W` `= (20.3 xx 7.1)/8.1`
  `= 17.79…`

 
`=> A`

Filed Under: M5 Scale Drawings (Y12), Ratio and Scale (Std2), Similarity, Similarity and Scale Tagged With: Band 4, num-title-ct-pathc, num-title-qs-hsc, smc-1105-30-Similarity, smc-1187-60-Similarity, smc-4746-50-Real world applications

Algebra, STD2 A2 2016 HSC 14 MC

The graph shows a line which has an equation in the form  `y = mx + c`.
 

Which of the following statements is true?

  1. `m` is positive and `c` is negative
  2. `m` is negative and `c` is positive
  3. `m` and `c` are both positive
  4. `m` and `c` are both negative
Show Answers Only

`=> A`

Show Worked Solution

`m` is the gradient and the line slopes to the right so `m` is positive.

`c` is the `y`-intercept which is negative.

`:.\ m` is positive and `c` is negative.

`=> A`

Filed Under: AM2 - Linear Relationships (Prelim), Cartesian Plane, Linear Equations and Basic Graphs (Std 1), Linear Equations and Basic Graphs (Std 2), Linear Relationships and Basic Graphs (Std2-2027) Tagged With: Band 4, num-title-ct-corea, num-title-qs-hsc, smc-1118-20-Identify graph/equation, smc-4422-20-Gradient, smc-6255-20-Equation of a line, smc-792-20-Equation of Line

Measurement, STD2 M1 2016 HSC 12 MC

A container is in the shape of a triangular prism which has a capacity of 12 litres. The area of the base is 240 cm².
 

What is the distance, `h`, between the two triangular ends of the container?

  1. 5 cm
  2. 20 cm
  3. 25 cm
  4. 50 cm
Show Answers Only

`=> D`

Show Worked Solution
♦♦ Mean mark 35%.

`text{1 mL = 1 cm}^3\ \ =>\ \ text{1 L = 1000 cm}^3`

`text(Volume)` `= Ah`
`12\ 000` `= 240 xx h`
`h` `= (12\ 000)/240`
  `= 50\ text(cm)`

 
`=> D`

Filed Under: MM2 - Perimeter, Area and Volume (Prelim), Perimeter, Area and Volume (Std 2), Volume, Volume, Mass and Capacity (Std2-2027) Tagged With: Band 5, num-title-ct-corea, num-title-qs-hsc, smc-4235-10-Prisms, smc-6304-40-Volume, smc-798-40-Volume

Statistics, STD2 S1 2016 HSC 7 MC

Which set of data is classified as categorical and nominal?

  1. blue, green, yellow
  2. small, medium, large
  3. 5.2 cm, 6 cm, 7.21 cm
  4. 4 people, 5 people, 9 people 
Show Answers Only

`A`

Show Worked Solution

`text(Categorical and nominal data is)`

♦♦ Mean mark 26%.

`text(qualitative and not ordered.)`

`=> A`

Filed Under: Classifying Data, Classifying Data (Std 1), Classifying Data (Std 2), Classifying Data (Y12), Data Classification, Investigation and Sampling Methods (Std2-2027), DS1 - Stats and society Tagged With: Band 6, common-content, num-title-ct-core, num-title-qs-hsc, smc-1127-20-Classifying Data, smc-5075-10-Categorical, smc-6309-20-Data Classification, smc-820-20-Classifying Data

Algebra, STD2 A1 2016 HSC 5 MC

Which expression is equivalent to  `2(3x-4) + 2`?

  1. `6x-2`
  2. `6x-4`
  3. `6x-6`
  4. `6x-10`
Show Answers Only

`C`

Show Worked Solution

`2(3x-4) + 2`

`= 6x-8 + 2`

`= 6x-6`
 

`=> C`

Filed Under: AM1 - Algebra (Prelim), Distributive Laws, Substitution and Other Equations (Std 1), Substitution and Other Equations (Std 2), Substitution and Other Equations (Std2-2027) Tagged With: Band 4, num-title-ct-corea, num-title-qs-hsc, smc-1116-50-Other Equations, smc-6234-50-Other Equations, smc-789-50-Other Equations

Measurement, STD2 M1 2016 HSC 1 MC

What is  208.345  correct to two significant figures?

  1. 208
  2. 210
  3. 208.34
  4. 208.35
Show Answers Only

`B`

Show Worked Solution

`208.345 = 210\ (2\ text(sig. fig.))`

♦♦ Mean mark 36%!!

`=> B`

 

Filed Under: Identify and Convert Between Units (Std2-2027), MM1 - Units of Measurement, Numbers of Any Magnitude, Units and Measurement Error (Std 1), Units and Measurement Error (Std 2) Tagged With: Band 5, num-title-ct-corea, num-title-qs-hsc, smc-1120-30-Significant Figures, smc-4232-50-Significant figures, smc-6303-50-Significant Figures, smc-797-30-Significant Figures

Functions, 2ADV F1 2016 HSC 11a

Sketch the graph of  `(x-3)^2 + (y + 2)^2 = 4.`  (2 marks)

--- 8 WORK AREA LINES (style=lined) ---

Show Answers Only

Show Worked Solution

`(x-3)^2 + (y + 2)^2 = 4\ \ text(is a circle),`

`text(centre)\ (3, -2),\ text(radius 2.)`
 

Filed Under: 4. Real Functions, Circles and Hyperbola, Further Functions and Relations (Y11), Graph Transformations (Adv-2027) Tagged With: Band 3, num-title-ct-pathc, num-title-qs-hsc, smc-4445-25-Sketch circle, smc-6408-80-Circles, smc-987-50-Circles

Functions, EXT1 F2 2007 HSC 2c

The polynomial  `P(x) = x^2 + ax + b`  has a zero at  `x = 2`. When  `P(x)`  is divided by  `x + 1`, the remainder is `18`.

Find the values of  `a`  and  `b`.  (3 marks)

--- 7 WORK AREA LINES (style=lined) ---

Show Answers Only

`a = -7\ \ text(and)\ \ b = 10`

Show Worked Solution

`P(x) = x^2 + ax + b`

`text(S)text(ince there is a zero at)\ \ x = 2,`

`P(2)` `=0`  
`2^2 + 2a + b` `= 0`  
`2a + b` `= -4`       `…\ (1)`

 
`P(-1) = 18,`

`(-1)^2-a + b` `= 18`  
`-a + b` `= 17`    `…\ (2)`

 
`text(Subtract)\ \ (1)-(2),`

`3a` `= -21`
`a` `= -7`

 
`text(Substitute)\ \ a = -7\ \ text{into (1),}`

`2(-7) + b` `= -4`
`b` `= 10`

 
`:.a = -7\ \ text(and)\ \ b = 10`

Filed Under: Polynomials, Remainder and Factor Theorems (Ext1), Roots, Remainders and Factors Tagged With: Band 3, num-title-ct-patha, num-title-qs-hsc, smc-1031-10-Factor Theorem, smc-1031-20-Remainder Theorem, smc-4242-10-Factor Theorem

Functions, 2ADV F1 2007 HSC 1f

Find the equation of the line that passes through the point `(1, 3)` and is perpendicular to  `2x + y + 4 = 0`.  (2 marks)

--- 5 WORK AREA LINES (style=lined) ---

Show Answers Only

`x-2y + 7 = 0`

Show Worked Solution
`2x + y + 4` `= 0`
`y` `= -2x-4`

  
`=>\ text(Gradient) = -2`

`:. text(⊥ gradient) = 1/2\ \ \ (m_1 m_2=-1)`
 

`text(Equation of line)\ \ m = 1/2, \ text(through)\ (1, 3):`

`y-y_1` `= m (x-x_1)`
`y-3` `= 1/2 (x-1)`
`y` `= 1/2 x + 5/2`
`2y` `= x + 5`
`:. x-2y + 5` `= 0`

Filed Under: 6. Linear Functions, Cartesian Plane, Linear Functions (Adv-2027), Linear Functions (Y11) Tagged With: Band 3, num-title-ct-pathc, num-title-qs-hsc, smc-4422-60-Perpendicular, smc-6214-05-Coordinate Geometry, smc-985-30-Coordinate Geometry

Functions, 2ADV F1 2007 HSC 1b

Solve  `2x-5> -3`  and graph the solution on a number line.  (2 marks)

--- 5 WORK AREA LINES (style=lined) ---

Show Answers Only

`x > 1`
 

Show Worked Solution
`2x-5` `> -3`
`2x` `> 2`
`x` `> 1`

 

Filed Under: Further Functions and Relations (Y11), Inequalities, Inequalities and Absolute Values, Linear Functions (Adv-2027) Tagged With: Band 2, num-title-ct-pathb, num-title-qs-hsc, smc-4385-10-Linear, smc-4385-50-Number line, smc-6214-08-Inequalities, smc-987-20-Inequalities

Functions, EXT1 F2 2015 HSC 11f

Consider the polynomials  `P(x) = x^3-kx^2 + 5x + 12`  and  `A(x) = x - 3`.

  1. Given that  `P(x)`  is divisible by  `A(x)`, show that  `k = 6`.  (1 mark)

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  2. Find all the zeros of  `P(x)`  when  `k = 6`.  (2 marks)

    --- 6 WORK AREA LINES (style=lined) ---

Show Answers Only
  1. `text(See Worked Solutions)`
  2. `3, 4, −1`
Show Worked Solution
i.    `P(x)` `= x^3-kx^2 + 5x + 12`
  `A(x)` `= x-3`

 
`text(If)\ P(x)\ text(is divisible by)\ A(x)\ \ =>\ \ P(3) = 0`

`3^3-k(3^2) + 5 xx 3 + 12` `= 0`
`27-9k + 15 + 12` `= 0`
`9k` `= 54`
`:.k` `= 6\ \ …\ text(as required)`

 

ii.  `text(Find all roots of)\ P(x)`

`P(x)=(x-3)*Q(x)`

`text{Using long division to find}\ Q(x):`
 

`:.P(x)` `= x^3-6x^2 + 5x + 12`
  `= (x-3)(x^2-3x − 4)`
  `= (x-3)(x-4)(x + 1)`

 
`:.\ text(Zeros at)\ \ \ x = -1, 3, 4`

Filed Under: Polynomials, Remainder and Factor Theorems (Ext1), Roots, Remainders and Factors Tagged With: Band 2, Band 3, num-title-ct-patha, num-title-qs-hsc, smc-1031-10-Factor Theorem, smc-4242-10-Factor Theorem, smc-4242-40-Long division

Plane Geometry, EXT1 2015 HSC 3 MC

Two secants from the point `P` intersect a circle as shown in the diagram.
  

What is the value of `x`?

  1. `2`
  2. `5`
  3. `7`
  4. `8`
Show Answers Only

`B`

Show Worked Solution

`text{Property: products of intercepts of secants from external point are equal}`

`x(x + 3)` `= 4(4 + 6)`
`x^2 + 3x` `= 40`
`x^2 + 3x-40` `= 0`
`(x-5)(x + 8)` `= 0`

 
`:.x = 5,\ \  (x>0)`

`=>B`

Filed Under: 2. Plane Geometry EXT1, Circle Geometry Tagged With: Band 5, num-title-ct-patha, num-title-qs-hsc, smc-4240-55-Secants

Functions, EXT1 F2 2015 HSC 1 MC

What is the remainder when `x^3-6x` is divided by `x + 3`?

  1. `-9`
  2. `9`
  3. `x^2-2x`
  4. `x^2-3x + 3`
Show Answers Only

`A`

Show Worked Solution
`text(Remainder)` `= P(-3)`
  `= (-3)^3-6(-3)`
  `= -27 + 18`
  `= -9`

 
`=> A`

Filed Under: Polynomials, Remainder and Factor Theorems (Ext1), Roots, Remainders and Factors Tagged With: Band 3, num-title-ct-patha, num-title-qs-hsc, smc-1031-20-Remainder Theorem, smc-4242-20-Remainder Theorem

Algebra, STD2 A1 2015 HSC 28d

The formula  `C = 5/9 (F-32)`  is used to convert temperatures between degrees Fahrenheit `(F)` and degrees Celsius `(C)`.

Convert 3°C to the equivalent temperature in Fahrenheit.   (2 marks)

--- 5 WORK AREA LINES (style=lined) ---

Show Answers Only

`37.4\ text(degrees)\ F`

Show Worked Solution
`C` `= 5/9(F-32)`
`F-32` `= 9/5C`
`F`  `= 9/5C + 32`

 
`text(When)\ \ C = 3,`

`F` `= (9/5 xx 3) + 32`
  `= 37.4\ text(degrees)\ F`

Filed Under: AM1 - Algebra (Prelim), Formula Rearrange, Formula Rearrange (Std 1), Formula Rearrange (Std 2), Formula Rearrange (Std2-2027), Linear, Substitution and Other Equations (Std 1), Substitution and Other Equations (Std 2), Substitution and Other Equations (Std2-2027) Tagged With: Band 4, num-title-ct-pathc, num-title-qs-hsc, smc-1116-20-Rearrange and Substitute, smc-1200-10-Linear, smc-1201-10-Linear, smc-4362-30-Rearrange and substitute, smc-6234-20-Rearrange and Substitute, smc-6236-10-Linear, smc-789-20-Rearrange and Substitute

Algebra, STD2 A2 2015 HSC 27c

Ariana’s parents have given her an interest‑free loan of $4800 to buy a car. She will pay them back by paying `$x` immediately and `$y` every month until she has repaid the loan in full.

After 18 months Ariana has paid back $1510, and after 36 months she has paid back $2770.

This information can be represented by the following equations.

`x + 18y = 1510`

`x + 36y = 2770`

  1. Graph these equations below and use to solve simultaneously for the values of `x` and `y`.   (2 marks)

         

    --- 1 WORK AREA LINES (style=lined) ---

  2. How many months will it take Ariana to repay the loan in full? (2 marks)

    --- 4 WORK AREA LINES (style=lined) ---

Show Answers Only
  1. `x = 250, \ y = 70`
  2. `text(65 months)`
Show Worked Solution

i.

 
`:.\ text(Solution is)\ \ x = 250, \ y = 70`
 

ii.  `text(Let)\ \ A = text(the amount paid back after)\ n\ text(months)`

`A = 250 + 70n`

♦ Mean mark 44%.

`text(Find)\ n\ text(when)\ A = 4800`

`250 + 70n` `= 4800`
`70n` `= 4550`
`n` `= 65`

 

`:.\ text(It will take Ariana 65 months to repay)`

`text(the loan in full.)`

Filed Under: Breakeven and Financial modelling, Linear Applications, Linear Functions (Adv-2027), Linear Functions (Y11) Tagged With: Band 5, common-content, num-title-ct-coreb, num-title-qs-hsc, smc-4421-30-Cost/Revenue, smc-6214-20-Other Real World Applications, smc-985-20-Other Linear Applications

Measurement, STD2 M7 2015 HSC 27a

At a particular time during the day, a tower of height 19.2 metres casts a shadow. At the same time, a person who is 1.65 metres tall casts a shadow 5 metres long.

  

What is the length of the shadow cast by the tower at that time?  (2 marks)

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`58\ text{m}`

Show Worked Solution

`text(Both triangles have right angles and a common)`

`text(angle to the ground.)`

`:.\ text{Triangles are similar (equiangular)}`

 

`text(Let)\ x =\ text(length of tower shadow)`

`x/5` `= 19.2/1.65\ \ text{(corresponding sides of similar triangles)}`

 

`x` `= (5 xx 19.2)/1.65`  
  `= 58.1818…`  
  `= 58\ text{m  (nearest m)}`  

Filed Under: M5 Scale Drawings (Y12), Ratio and Scale (Std2), Similarity, Similarity and Scale Tagged With: Band 4, num-title-ct-pathc, num-title-qs-hsc, smc-1105-30-Similarity, smc-1187-60-Similarity, smc-4746-50-Real world applications

Measurement, STD2 M1 2015 HSC 26f

Approximately 71% of Earth’s surface is covered by water. Assume Earth is a sphere with a radius of 6400 km.

Calculate the number of square kilometres covered by water.  (2 marks)

--- 4 WORK AREA LINES (style=lined) ---

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`3.7 xx 10^8\ text(km²)\ \ text{(nearest km²)}`

Show Worked Solution

`text(Surface area of Earth)`

`= 4pir^2`

`= 4pi xx 6400^2`

 

`:.\ text(Surface covered by water)`

`= text(71%) xx 4pi xx 6400^2`

`= 365\ 450\ 163.7…`

`= 3.7 xx 10^8\ text(km²)\ \ text{(nearest km²)}`

Filed Under: Areas and Volumes (Harder), Perimeter, Area and Volume (Std 2), Surface Area (Std2-2027) Tagged With: Band 4, num-title-ct-pathb, num-title-qs-hsc, smc-4234-50-SA (sphere), smc-6484-20-Surface Area (Circular Measure), smc-798-25-Surface Area

Probability, STD2 S2 2015 HSC 26e

The table shows the relative frequency of selecting each of the different coloured jelly beans from packets containing green, yellow, black, red and white jelly beans.

\begin{array} {|c|c|}
\hline
\rule{0pt}{2.5ex} \textit{Colour} \rule[-1ex]{0pt}{0pt} & \textit{Relative frequency} \\
\hline
\rule{0pt}{2.5ex} \text{Green} \rule[-1ex]{0pt}{0pt} & 0.32 \\
\hline
\rule{0pt}{2.5ex} \text{Yellow} \rule[-1ex]{0pt}{0pt} & 0.13 \\
\hline
\rule{0pt}{2.5ex} \text{Black} \rule[-1ex]{0pt}{0pt} & 0.14 \\
\hline
\rule{0pt}{2.5ex} \text{Red} \rule[-1ex]{0pt}{0pt} &  \\
\hline
\rule{0pt}{2.5ex} \text{White} \rule[-1ex]{0pt}{0pt} & 0.24 \\
\hline
\end{array}

  1. What is the relative frequency of selecting a red jelly bean?  (1 mark)

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  2. Based on this table of relative frequencies, what is the probability of NOT selecting a black jelly bean?  (1 mark)

    --- 2 WORK AREA LINES (style=lined) ---

Show Answers Only
  1. \(0.17\)
  2. \(0.86\)
Show Worked Solution

i.  \(\text{Relative frequency of red}\)

\(= 1-(0.32 + 0.13 + 0.14 + 0.24)\)

\(= 1-0.83\)

\(= 0.17\)

 

ii.  \(P\text{(not selecting black)}\)

\(= 1-P\text{(selecting black)}\)

\(= 1-0.14\)

\(= 0.86\)

Filed Under: Combinations and Single Stage Events (Std 2), Probability, Relative Frequency, Relative Frequency (Std 1), Relative Frequency (Std 2), Relative Frequency (Y11), Single and Multi-Stage Events (Std 1), Single stage events Tagged With: Band 3, Band 4, common-content, num-title-ct-core, num-title-qs-hsc, smc-1133-20-Games of Chance, smc-1135-05-Simple Probability, smc-4225-20-Complementary events, smc-4225-35-Relative frequency, smc-827-20-Games of Chance, smc-828-10-Simple Probability, smc-990-20-Games of Chance

Financial Maths, STD2 F4 2015 HSC 26d

A family currently pays $320 for some groceries.

Assuming a constant annual inflation rate of 2.9%, calculate how much would be paid for the same groceries in 5 years’ time.  (2 marks)

Show Answers Only

`$369.17\ \ text{(nearest cent)}`

Show Worked Solution
`FV` `= PV(1 + r)^n`
  `= 320(1.029)^5`
  `= $369.1703…`
  `= $369.17\ \ text{(nearest cent)}`

Filed Under: Compound Interest, Compound Interest and Shares (Std2), F2 Investment (Y12), FM2 - Investing, Modelling Investments and Loans (Y12) Tagged With: Band 4, common-content, num-title-ct-coreb, num-title-qs-hsc, smc-1002-20-FV Formula, smc-1108-20-FV Formula, smc-4334-10-Find FV, smc-817-20-FV Formula

Algebra, STD2 A1 2015 HSC 24 MC

Consider the equation  `(2x)/3-4 = (5x)/2 + 1`.

Which of the following would be a correct step in solving this equation?

  1. `(2x)/3-3 = (5x)/2`
  2. `(2x)/3 = (5x)/2 + 5`
  3. `2x-4 = (15x)/2 + 3`
  4. `(4x)/6-8 = 5x + 2`
Show Answers Only

`B`

Show Worked Solution
`(2x)/3-4` `= (5x)/2 + 1`
`(2x)/3` `= (5x)/2 + 5`

 
`=>B`

Filed Under: Algebraic Fractions, Linear and Other Equations, Substitution and Other Equations (Std 1), Substitution and Other Equations (Std 2), Substitution and Other Equations (Std2-2027) Tagged With: Band 4, common-content, num-title-ct-pathc, num-title-qs-hsc, smc-1116-30-Algebraic Fractions, smc-4402-40-Multiple fractions, smc-6234-30-Algebraic Fractions, smc-789-30-Algebraic Fractions

Measurement, STD2 M6 2015 HSC 22 MC

The area of the triangle shown is 250 cm².
 


 

What is the value of `x`, correct to the nearest whole number?

  1. `11`
  2. `18`
  3. `22`
  4. `24`
Show Answers Only

`D`

Show Worked Solution

`text(Using)\ \ \ A = 1/2ab\ sin\ C`

♦ Mean mark 42%.
`250` `= 1/2 xx 30x\ sin\ 44^@`
`250` `= 15x\ sin\ 44 ^@`
`:.x` `= 250/(15\ sin\ 44^@)`
  `= 23.99…\ text(m)`

 
`=>D`

Filed Under: Non Right-Angled Trig, Non-Right Angled Trig, Non-Right Angled Trig (Std2) Tagged With: Band 5, num-title-ct-pathc, num-title-qs-hsc, smc-4553-30-Sine Rule (Area), smc-804-30-Sine Rule (Area)

Financial Maths, STD2 F4 2015 HSC 17 MC

What amount must be invested now at 4% per annum, compounded quarterly, so that in five years it will have grown to  $60 000?

  1. $8919
  2. $11 156
  3. $49 173
  4. $49 316
Show Answers Only

`C`

Show Worked Solution

`text(Using)\ \ FV = PV(1 + r)^n`

`r` `= text(4%)/4` `= text(1%) = 0.01\ text(per quarter)`
`n` `= 5 xx 4` `= 20\ text(quarters)`

 

`60\ 000` `= PV(1 + 0.01)^(20)`
`:.PV` `= (60\ 000)/1.01^(20)`
  `= $49\ 172.66…`

`⇒ C`

Filed Under: Compound Interest, Compound Interest and Shares (Std2), F2 Investment (Y12), FM4 - Credit and Borrowing, Modelling Investments and Loans (Y12) Tagged With: Band 4, common-content, num-title-ct-coreb, num-title-qs-hsc, smc-1002-20-FV Formula, smc-1108-20-FV Formula, smc-4334-30-Find PV, smc-817-20-FV Formula

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