This blog is managed by Song Hock Chye, author of Improve Your Thinking Skills in Maths (P1-P3 series), which is published and distributed by EPH.

Wednesday, January 21, 2009

Tao Nan School P5 SA2 2007 Math Q43

The ratio of Liling’s money and Yingqi’s money was 7:4. When Liling gave $100 to Yingqi, the ratio became 5:6. How much money did Liling have at first?

Solution

Liling : Yingqi
7 : 4 (before ----- 11 units)
5: 6 (after ----- 11 units)

As can be seen from above, 2 units were given.

2 units ----- $100
1 unit ----- $100 divided by 2 = $50

(Liling at first) 7 units ----- 7 x $50 = $350

Answer: Liling had $350 at first.

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