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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.

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