PSLE
On Monday, the number of adults to girls to boys visiting a theme park was 3 : 10 : 10. On Tuesday, the number of adults visiting the theme park remained the same. However, the number of girls increased by 40% and the number of boys decreased by 20%.

1. What was the ratio of the number of adults to girls to boys visiting the theme park on Tuesday?
2. On Monday, 720 girls and boys visited the theme park. What was the total number of visitors at the theme park on Tuesday?

	Adults	Girls	Boys
Before	3 u	10 u	10 u
Change		+ 4 u	- 2 u
After	3 u	14 u	8 u

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

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

Number of girls on Tuesday
= 10 u + 4 u
= 14 u

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

On Tuesday
Adults : Girls : Boys
3 : 14 : 8

(b)
Number of girls and boys on Monday
= 10 u + 10 u
= 20 u

20 u = 720

1 u = 720 ÷ 20 = 36

Total number of visitors on Tuesday
= 3 u + 14 u + 8 u
= 25 u
= 25 x 36
= 900

Answer(s): (a) 3 : 14 : 8; (b) 900