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Ratio Changes

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15

Ratio increase & scaling

Increasing of decreasing given a ratio

Calculating the cheapest option or best value

Class notes, pdf

Recipe example | pdf
Practice C | pdf
Practice D | pdf

p62 Ex 4.05

NuLake p28, 29

 

Splitting up given a ratio

Example 1

Share an interitance of $48 into the ratio 5:1

 

 

 

Steps

5 + 1 = 6 parts

1) Add the ratio 'parts' together (how many 'parts' total?)

$48 ÷ 6parts = $8

2) What is 1 'part' worth?

5:1

3) Share the ratio

5 x $8 : 1 x $8

 

$40 : $8

Write the ratio in the correct order
(if 1:5 then $8:$40)

 

 

 

 

Example 2

Bob & Bill build a boat. Bob works for 12hr and Bill works for 30hr
They sell the boat for $840.
If they share the money according to the time worked, how much will each person get?

 

 

 

 

 

Steps

12 + 30 = 42 parts

1) Add the ratio 'parts' together (how many 'parts' total?)

$840 ÷ 42parts = $20

2) What is 1 'part' worth?

12:30

3) Share the ratio Bob:Bill

12 x $20 : 30 x $20

 

$240 : $600

Bob gets $240 and Bill gets $600

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