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, March 25, 2009

Tao Nan School P5 SA2 2006 Math Q46

Cherie had 3 times as much money as Jolene. After Cherie spent $40 and Jolene spent $8, Jolene had 3 times as much money as Cherie. How much money did Cherie have at first?

Solution



Jolene (before) ----- 3 units + $8
*Cherie (before) had 3 times as much as Jolene -----
(3 x 3 units) + (3 x $8) = 9 units + $24

Cherie (before) – Cherie (after) ----- $40 (spent)
(9 units + $24) – (1 unit) ----- $40
8 units + $24 ------ $40
8 units ----- $40 - $24 = $16
1 unit ----- $16 divided by 8 = $2

Cherie (at first)
9 units + $24
= (9 x $2) + $24
= $18 + $24
= $42

Answer: Cherie had $42 at first.

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