If \(d=\sqrt{\dfrac{h}{5}}\), what is the value of \(d\), correct to one decimal place, when \(h=28\)?
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- 2.4
- 2.8
- 5.6
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If \(d=\sqrt{\dfrac{h}{5}}\), what is the value of \(d\), correct to one decimal place, when \(h=28\)?
\(B\)
\(\text{When}\ h=28:\)
| \(d\) | \(=\sqrt{\dfrac{h}{5}}\) |
| \(d\) | \(=\sqrt{\dfrac{28}{5}}\) |
| \(=2.366…\) | |
| \(=2.4\ (\text{1 deccimal place})\) |
\(\Rightarrow B\)
If \(x=-2.531\), what is the value of \(x^2\) rounded to 2 decimal places?
\(D\)
| \( x^2\) | \(=(-2.531)^2 \) | |
| \(=6.405\ldots \) | ||
| \(=6.41\) |
\(\Rightarrow D\)
What is the value of `(a + b)/(ab)` if `a =-2.1` and `b =-3.6`, correct to 1 decimal place? (2 marks)
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`-0.8`
| `(a + b)/(ab)` | `= (-2.1-3.6)/(-2.1 xx -3.6)` |
| `= (-5.7)/7.56` | |
| `= -0.753…` | |
| `= -0.8` |
If `S = V_0 (1-r)^n`, find `S` given `V_0 = $42\ 000, r = 0.16 and n = 4`. Give your answer to the nearest cent. (2 marks)
`$20\ 910.60\ text{(to nearest cent)}`
| `S` | `= V_0 (1-r)^n` |
| `= 42\ 000 (1-0.16)^4` | |
| `= 42\ 000 (0.84)^4` | |
| `= $20\ 910.597…` | |
| `= $20\ 910.60\ \ text{(to nearest cent)}` |
It is given that `I = 3/2 MR^2`.
What is the value of `I` when `M = 26.55` and `R = 3.07`, correct to two decimal places?
A. `375.35`
B. `3246.08`
C. `9965.45`
D. `14\ 948.18`
`A`
`I= 3/2 xx 26.55 xx (3.07)^2= 375.346…`
`=> A`
If `A = P(1 + r)^n`, find `A` given `P = $300`, `r = 0.12` and `n = 3` (give your answer to the nearest cent). (2 marks)
`$421.48\ \ text{(nearest cent)}`
| `A` | `= P(1 + r)^n` |
| `= 300(1 + 0.12)^3` | |
| `= 300(1.12)^3` | |
| `= 421.478…` | |
| `= $421.48\ \ text{(nearest cent)}` |
What is the value of `5a^2-b`, if `a =-4` and `b = 3`. (2 marks)
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`77`
| `5a^2-b` | `= 5(-4)^2-3` |
| `= 5 xx 16-3` | |
| `= 77` |
If `V = 4/3 pir^3`, what is the value of `V` when `r = 2`, correct to two decimal places?
`D`
`V = 4/3 pir^3`
`text(When)\ \ r = 2,`
`V= 4/3 pi xx 2^3= 33.510\ …=33.51\ text{(2 dp)}`
`=> D`
What is the value of `(a-b)/4`, if `a = 240` and `b = 56`?
`B`
`(a-b)/4= (240-56)/4= 46`
`=> B`
If `K = Ft^3`, `F = 5` and `t = 0.715`, what is the value of `K` correct to three significant figures?
`D`
| `K` | `= Ft^3` |
| `= 5 xx (0.715)^3= 1.8276…` | |
| `= 1.83\ \ text{(3 sig figures)}` |
`=> D`
This shape is made up of a right-angled triangle and a regular hexagon.
The area of a regular hexagon can be estimated using the formula `A = 2.598H^2` where `H` is the side-length.
Calculate the total area of the shape using this formula. (3 marks)
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`22.784\ text(cm)^2`
`text(Area) = 2.598H^2`
`text(Using Pythagoras:)`
| `H^2` | `= 2^2 + 2^2= 8` |
| `H` | `= sqrt 8` |
`text(Area of hexagon)= 2.598 xx (sqrt 8)^2= 20.784\ text(cm)^2`
`text(Area of triangle)= 1/2 bxx h= 1/2 xx 2 xx 2= 2\ text(cm)^2`
`:.\ text(Total Area)= 20.784 + 2= 22.784\ text(cm)^2`
What is the value of `sqrt((x+2y)/(8y))` if `x = 5.6` and `y = 3.1`, correct to 2 decimal places?
`A`
| `sqrt((x+2y)/(8y))` | `=sqrt((5.6+(2 xx 3.1))/((8 xx 3.1)))` |
| `=sqrt(11.8/24.8)=0.6897…` |
`=> A`
If `M=-9`, what is the value of `(3M^2+5M)/6`
`C`
| `(3M^2+5M)/6` | `=(3xx(–9)^2+5xx(–9))/6` |
| `=((3xx81)-45)/6` | |
| `=33` |
`=> C`