PSLE
On Wednesday, the number of adults to girls to boys visiting a museum was 1 : 10 : 8. On Thursday, the number of adults visiting the museum remained the same. However, the number of girls increased by 40% 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 Thursday?
2. On Wednesday, 612 girls and boys visited the museum. What was the total number of visitors at the museum on Thursday?

	Adults	Girls	Boys
Before	1 u	10 u	8 u
Change		+ 4 u	- 2 u
After	1 u	14 u	6 u

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

Decrease in the number of boys
= 25% x 8 u
= ²⁵₁₀₀ x 8 u
= 2 u

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

Number of boys on Thursday
= 8 u - 2 u
= 6 u

On Thursday
Adults : Girls : Boys
1 : 14 : 6

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

18 u = 612

1 u = 612 ÷ 18 = 34

Total number of visitors on Thursday
= 1 u + 14 u + 6 u
= 21 u
= 21 x 34
= 714

Answer(s): (a) 1 : 14 : 6; (b) 714