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.

## Saturday, January 12, 2008

### Ai Tong School P5 Math CA1 2006 (Q48)

Alfred sold thrice as many \$5 T-shirts as \$10 T-Shirts. He also sold twice as many \$10 T-shirts as \$20 T-shirts. He collected \$160 more from selling \$5 T-shirts than from selling \$20 T-shirts.

a) How much money did he collect from selling \$5 T-shirts?
b) How many T-shirts did he sell altogether?

Solution

He collected \$160 more selling \$5 T-shirts than from selling \$20 T-shirts.

6 units – 4 units ----- \$160

2 units ----- \$160

1 unit ----- \$160 divided by 2 = \$80

Q(a) How much money did he collect from selling \$5 T-shirts?

6 units ----- 6 x \$80 = \$480

Answer: He collected \$480 from selling \$5 T-shirts.

Q(b) How many T-shirts did he sell altogether?

(\$5 T-shirts) ----- \$480
\$480 divided by \$5 = 96 (T-shirts)

(\$10 T-shirts)
4 units ----- 4 x \$80 = \$320
\$320 divided by \$10 = 32 (T-shirts)

(\$20 T-shirts)
4 units ----- 4 x \$80 = \$320
\$320 divided by \$20 = 16 (T-shirts)

Total number of T-shirts sold

96 + 32 + 16 = 144

Answer: He sold 144 T-shirts altogether.