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Measurement, STD1 M4 2021 HSC 11

Chocolate of a particular brand can be bought in three different sizes.

Option 1: 100 grams for $1.50

Option 2: 300 grams for $4.20

Option 3: 500 grams for $7.25

Which option gives the lowest price per 100 grams? Justify your answer with calculations.  (2 marks)

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`text(Option 2 is the cheapest.)`

Show Worked Solution

`text(Compare prices per 100 grams:)`

`text(Option 1) = $1.50`

`text(Option 2) = 4.20 ÷ 3 = $1.40`

`text(Option 3) = 7.25 ÷ 5 = $1.45`

`:.\ text(Option 2 is the cheapest.)`

Measurement, STD2 M7 SM-Bank 16

A refreshment stand at the market sells its iced tea in four different sizes.
 

Showing calculations, find which serving size offers the cheapest iced tea.   (2 marks)

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`text(375 mL)`

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`text(Consider the price per mL of each option)`

`text(150 mL :)\ \ 1.50/150 = 1\ text(cent/mL)`

`text(750 mL :)\ \ 6.10/750 = 0.81\ text(cent/mL)`

`text(375 mL :)\ \ 3.00/375 = 0.8\ text(cent/mL)`

`text(200 mL :)\ \ 1.80/200 = 0.9\ text(cent/mL)`

 

`:.\ text(375 mL serving size offers the cheapest price)`

Measurement, STD2 M7 SM-Bank 15 MC

A brand of pasta is sold in two different packets.
 

What is the difference in the price per kilogram of these two packets?

  1. $1.50
  2. $3.00
  3. $3.60
  4. $7.20
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`B`

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`text(Convert to price per kg:)`

`text(Packet 1)`

`200\ text(g) = $1.80`

`1\ text(kg) = 5 xx 1.80 = $9`

 

`text(Packet 2)`

`750\ text(g) = $9`

`100\ text(g) = 9.00 ÷ 7.5 = $1.20`

`1\ text(kg) = 1.20 xx 10 = $12`

 

`:.\ text(Difference per kg)`

`= 12 – 9`

`= $3.00`
 

`=> B`

Measurement, STD2 M7 SM-Bank 14

Reece looks at the price of four sunscreens.
 

 
Which sunscreen is the cheapest per litre? Show your calculations.   (2 marks)

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`text(Sport sunscreen)`

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`text(Sun)\ =1090/1200 = 0.91\ text(c/mL)`

STRATEGY: Finding the cost per mL is much more efficient in answering this question than finding the cost per litre.

`text(Sport)\ =540/600 = 0.9\ text(c/mL)`

`text(Block)\ =475/500 = 0.95\ text(c/mL)`

`text(Wet)\ =740/750 = 0.99\ text(c/mL)`

 

`:.\ text(Sport sunscreen is the cheapest.)`

Measurement, STD1 M4 2019 HSC 3 MC

Sugar is sold in four different sized packets.

Which is the best buy?

  1.  100 g for $0.40
  2.  500 g for $1.65
  3.  1 kg for $3.50
  4.  2 kg for $6.90
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`B`

Show Worked Solution

`text(Price per kilogram:)`

`100\ text(g) -> 10 xx 0.40 = $4.00`

`500\ text(g) -> 2 xx 1.65 = $3.30`

`1\ text(kg) -> $3.50`

`2\ text(kg) -> 6.90 ÷ 2 = $3.45`

`=> B`