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.

Thursday, October 02, 2008

Catholic High Sch 2006 PSLE Math Prelim Q42

It takes Martin 5 hours to fix a jigsaw. If Jeremy helps him, they would take 3 hours to fix the jigsaw together. How long will Jeremy take to fix the jigsaw by himself?


5h ----- 1 whole
3h ----- 3/5

Jeremy fixed the other 2/5
2/5 ----- 3h
1/5 ----- 3h/2
5/5 ----- (3h/2) x 5 = 7.5h

Answer: It will take Jeremy 7.5h

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