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.

Tuesday, July 20, 2010

ACS Primary 2009 PSLE Math PrelimPaper 2 Q15

There were 192 apples and pears in a box. John removed 2/5 of the apples from the box and he added 24 pears into the box. As a result, there was an equal number of apples and pears left in the box. How many more apples than pears were there in the box at first?

Solution



5 units + 1 part --> 192
3 units --> 1 part + 24

5 units + 1 part --> 192
3 units - 1 part --> 24

(5 units + 3 units) + (1 part - 1part) --> 192 + 24
8 units --> 216
1 unit --> 216 divided by 8 = 27

At first
(Apples) 5 units --> 5 x 27 = 135
(Pears) 192 - 135 = 57

Apples more than pears
--> 135 - 57 = 78

Answer: 78 more apples


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