PSLE
On Saturday, the number of adults to girls to boys visiting a safari park was 1 : 10 : 5. On Sunday, the number of adults visiting the safari park remained the same. However, the number of girls decreased by 40% and the number of boys increased by 40%.

1. What was the ratio of the number of children to adults visiting the safari park on Sunday?
2. On Saturday, 555 girls and boys visited the safari park. What was the total number of child visitors at the safari park on Sunday?

	Adults	Girls	Boys
Before	1 u	10 u	5 u
Change		- 4 u	+ 2 u
After	1 u	6 u	7 u

(a)
Increase in the number of girls
= 40% x 10 u
= ⁴⁰₁₀₀ x 10 u
= 4 u

Decrease in the number of boys
= 40% x 5 u
= ⁴⁰₁₀₀ x 5 u
= 2 u

Number of girls on Sunday
= 10 u - 4 u
= 6 u

Number of boys on Sunday
= 5 u + 2 u
= 7 u

Number of children on Sunday
= 6 u + 7 u
= 13 u

On Sunday
Children : Adults
13 : 1

(b)
Number of girls and boys on Saturday
= 10 u + 5 u
= 15 u

15 u = 555

1 u = 555 ÷ 15 = 37

Total number of child visitors on Sunday
= 13 u
= 13 x 37
= 481

Answer(s): (a) 13 : 1; (b) 481