PSLE
On Tuesday, the number of adults to girls to boys visiting a museum was 7 : 8 : 4. On Wednesday, the number of adults visiting the museum remained the same. However, the number of girls increased by 50% and the number of boys decreased by 25%.

1. What was the ratio of the number of adults to girls to boys visiting the museum on Wednesday?
2. On Tuesday, 588 girls and boys visited the museum. What was the total number of visitors at the museum on Wednesday?

	Adults	Girls	Boys
Before	7 u	8 u	4 u
Change		+ 4 u	- 1 u
After	7 u	12 u	3 u

(a)
Increase in the number of girls
= 50% x 8 u
= ⁵⁰₁₀₀ x 8 u
= 4 u

Decrease in the number of boys
= 25% x 4 u
= ²⁵₁₀₀ x 4 u
= 1 u

Number of girls on Wednesday
= 8 u + 4 u
= 12 u

Number of boys on Wednesday
= 4 u - 1 u
= 3 u

On Wednesday
Adults : Girls : Boys
7 : 12 : 3

(b)
Number of girls and boys on Tuesday
= 8 u + 4 u
= 12 u

12 u = 588

1 u = 588 ÷ 12 = 49

Total number of visitors on Wednesday
= 7 u + 12 u + 3 u
= 22 u
= 22 x 49
= 1078

Answer(s): (a) 7 : 12 : 3; (b) 1078