Wednesday, April 18, 2012

P5 Maths - Ratio

The number of stickers Raymond had to Cadence was 5 : 3. After Cadence gave away 39 stickers, the ratio became 6 : 1. How many stickers did both of them had altogether in the end?

For this qn, there is a "Before and After" ratio given. One of the subject in the ratio will remain unchanged.


Before, Raymond : Cadence
= 5 : 3 (multiply by 6)
= 30 : 18

After, Raymond : Cadence
= 6 : 1 ( multiply by 5)
= 30 : 5

Raymond did not have any changes made to his stickers. Hence the before and after units are made the same.

Cadence,

18u – 5u = 13u
13u --> 39 stickers ( Cadence gave away)
1 u --> 3 stickers

In the end,

30u + 5u = 35u
35u --> 35 * 3 = 105 stickers

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