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.

## Friday, November 23, 2007

### Raffles Girls’ Primary School 2005 PSLE Math Prelim Question

A school staged a play at Victoria Theatre on two evenings. On the first evening, there were 80 more boys than girls in the audience. On the second evening, the number of boys decreased by 10% while the number of girls increased by 20%. If there were 1542 boys and girls on the second evening, what was the total sum of money collected from the sale of the tickets on the two evenings if each ticket cost \$30?

On 2nd Evening,

90% + 72 (boys) + 120% (girls) ---- 1542

210% + 72 ----- 1542

210% ----- 1542 - 72 = 1470

1% ----- 1470 divided by 210 = 7 (all important 1%)

Total number of children (1st evening + 2nd evening)

100% + 80 (boys, 1st evening) + 100% (girls, 1st evening) + 90% + 72 (boys, 2nd evening) + 120% (girls, 2nd evening)

= 410% + 80 + 72
= (410% x 7) + 152

= 3022

1 ticket cost \$3022. Therefore total amount collected for 2 evenings

\$30 x 3022 = \$90660

Answer: \$90600 was collected for both evenings.