PSLE
On Monday, the number of adults to girls to boys visiting a tourist attraction was 1 : 8 : 10. On Tuesday, the number of adults visiting the tourist attraction remained the same. However, the number of girls increased by 25% and the number of boys decreased by 20%.

1. What was the ratio of the number of adults to girls to boys visiting the tourist attraction on Tuesday?
2. On Monday, 576 girls and boys visited the tourist attraction. What was the total number of visitors at the tourist attraction on Tuesday?

	Adults	Girls	Boys
Before	1 u	8 u	10 u
Change		+ 2 u	- 2 u
After	1 u	10 u	8 u

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

Decrease in the number of boys
= 20% x 10 u
= ²⁰₁₀₀ x 10 u
= 2 u

Number of girls on Tuesday
= 8 u + 2 u
= 10 u

Number of boys on Tuesday
= 10 u - 2 u
= 8 u

On Tuesday
Adults : Girls : Boys
1 : 10 : 8

(b)
Number of girls and boys on Monday
= 8 u + 10 u
= 18 u

18 u = 576

1 u = 576 ÷ 18 = 32

Total number of visitors on Tuesday
= 1 u + 10 u + 8 u
= 19 u
= 19 x 32
= 608

Answer(s): (a) 1 : 10 : 8; (b) 608