 ## Question

primary 6 | Maths | Ratio

Anyone can contribute an answer, even non-tutors.

##### Jong

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Pls help me asap

Date Posted: 5 months ago
Views: 50

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Hope this helps
Date Posted: 5 months ago
Ratio of Grace \$ : Chris \$ : Total \$ : Difference
= 3 : 7 : 10 : 4
Ratio of Grace \$ : Chris \$ : Total \$ : Difference
= 1 : 4 : 5 : 3
Now since they each bought a book of the same cost, the amount spent is the same. So the difference between their money left and difference between their money at first is the same. It doesn't change.
We have to make the differences for each ratio to become the same.
Common multiple of 4 and 3 is 12 because 4 x 3 = 12
Multiply by 3, Ratio of Grace \$ : Chris \$ : Total \$ : Difference before buying book
= 9 : 21 : 30 : 12
Multiply by 4, Ratio of Grace \$ : Chris \$ : Total \$ : Difference after buying book
= 4 : 16 : 20 : 12
9 - 4 = 5, and 21 - 16 = 5. So they each spent 5 units on the book.
5 units = \$45 so 1 unit = \$45 ÷ 5 = \$9
Total amount they had at first = 30 units
= \$9 x 30 = \$270 