PSLE
On Wednesday, the number of children to women to men visiting a safari park was 1 : 10 : 12. On Thursday, the number of children visiting the safari park remained the same. However, the number of women decreased by 50% and the number of men increased by 50%.

1. What was the ratio of the number of adults to children visiting the safari park on Thursday?
2. On Wednesday, 506 women and men visited the safari park. What was the total number of adult visitors at the safari park on Thursday?

	Children	Women	Men
Before	1 u	10 u	12 u
Change		- 5 u	+ 6 u
After	1 u	5 u	18 u

(a)
Increase in the number of women
= 50% x 10 u
= ⁵⁰₁₀₀ x 10 u
= 5 u

Decrease in the number of men
= 50% x 12 u
= ⁵⁰₁₀₀ x 12 u
= 6 u

Number of women on Thursday
= 10 u - 5 u
= 5 u

Number of men on Thursday
= 12 u + 6 u
= 18 u

Number of adults on Thursday
= 5 u + 18 u
= 23 u

On Thursday
Adults : Children
23 : 1

(b)
Number of women and men on Wednesday
= 10 u + 12 u
= 22 u

22 u = 506

1 u = 506 ÷ 22 = 23

Total number of adult visitors on Thursday
= 23 u
= 23 x 23
= 529

Answer(s): (a) 23 : 1; (b) 529