PSLE
On Friday, the number of adults to boys to girls visiting a safari park was 7 : 8 : 2. On Saturday, the number of adults visiting the safari park remained the same. However, the number of boys decreased by 25% and the number of girls increased by 50%.

1. What was the ratio of the number of children to adults visiting the safari park on Saturday?
2. On Friday, 400 boys and girls visited the safari park. What was the total number of child visitors at the safari park on Saturday?

	Adults	Boys	Girls
Before	7 u	8 u	2 u
Change		- 2 u	+ 1 u
After	7 u	6 u	3 u

(a)
Increase in the number of boys
= 25% x 8 u
= ²⁵₁₀₀ x 8 u
= 2 u

Decrease in the number of girls
= 50% x 2 u
= ⁵⁰₁₀₀ x 2 u
= 1 u

Number of boys on Saturday
= 8 u - 2 u
= 6 u

Number of girls on Saturday
= 2 u + 1 u
= 3 u

Number of children on Saturday
= 6 u + 3 u
= 9 u

On Saturday
Children : Adults
9 : 7

(b)
Number of boys and girls on Friday
= 8 u + 2 u
= 10 u

10 u = 400

1 u = 400 ÷ 10 = 40

Total number of child visitors on Saturday
= 9 u
= 9 x 40
= 360

Answer(s): (a) 9 : 7; (b) 360