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.

## Sunday, December 23, 2007

### Anglo-Chinese School (Primary) P5 SA2 2006 Math Question (Q44)

Michael and Luke had 600 stickers altogether. After Michael gave away 40 of his stickers, 2/5 of the number of Luke’s stickers was equal to 2/3 of Michael’s stickers.

a) How many stickers did Michael have at first?

b) How many stickers did Luke buy so that the ratio of the number of Luke’s stickers to the number of Michael’s stickers is now 7 : 3?

Solution

8 units + 40 ----- 600

8 units ----- 600 – 40 = 560

1 unit ----- 560 divided by 8 = 70

Q(a)

Michael had at first

3 units + 40 ----- (3 units x 70) + 40

= 210 + 40 = 250

Answer: Michael had 250 stickers at first.

Q(b)

After Michael gave away 40 stickers and before Luke bought some stickers, the ratio of the number of Luke’s stamps to the number of Michael’s stamps was 5 : 3.

After Luke bought some stamps, the ratio was 7 : 3.

Luke bought 2 units ----- 2 units x 70 = 140

Answer: Luke bought 140 stamps.