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 22, 2008

Henry Park Pri Sch 2007 PSLE Math Prelim Q43

Four children, Angela, Belinda, Cristobel and Dorothy shared $240. Angela received ½ of the total amount of money received by Belinda, Cristobel and Dorothy. Belinda received 2/3 of the total amount of money received by Cristobel and Dorothy. Cristobel received 3 times as much money as Dorothy.
a) How much money did Dorothy receive?
b) What fraction of Angela’s money is Dorothy’s money if Angela gave $20 to Dorothy?

Solution



10 units ----- $240
1 unit ----- $240 divided by 10 = $24

a) Dorothy
1 unit ----- $24.

Answer: Dorothy received $24.

b) (Angela) 3 1/3 units ----- $24 x 3 1/3 = $80
(Dorothy) 1 unit ----- $24
If Angela gives Dorothy $20,
Angela ----- $80 – $20 = $60
Dorothy ----- $24 + 20 = $44
$44 / $60 = 11/15 (Answer)

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