Pei Chun Public Sch 2007 PSLE Math Prelim Q41

The ratio of the number of Andrew’s stickers to the number of Eunice’s stickers was 1 : 5. Then their mother gave Eunice 12 more stickers and Andrew 5 more stickers. The ratio of the number of Andrew’s stickers to the number of Eunice’s stickers became 1 : 4. How many stickers did Andrew have in the end?

Solution

Andrew (before) 1 unit + 5 ----- 1 part (after) (multiply by 4)
Eunice (before) 5 units +12 ----- 4 parts (after)

Andrew (before) 4 units + 20 ----- 4 parts (after)
Eunice (before) 5 units + 12 ----- 4 parts (after)

Comparing Eunice with Andrew -----
(Eunice) 5 units + 12 ----- 4 units + 20 (Andrew)

5 units – 4 units ----- 20 – 12
1 unit = 8

Andrew in the end -----
1 unit + 5
= 8 + 5
= 13

Answer: Andrew had 13 stickers in the end.