PSLE
On Thursday, the number of children to men to women visiting a museum was 7 : 5 : 12. On Friday, the number of children visiting the museum remained the same. However, the number of men decreased by 40% and the number of women increased by 50%.

1. What was the ratio of the number of adults to children visiting the museum on Friday?
2. On Thursday, 816 men and women visited the museum. What was the total number of adult visitors at the museum on Friday?

	Children	Men	Women
Before	7 u	5 u	12 u
Change		- 2 u	+ 6 u
After	7 u	3 u	18 u

(a)
Increase in the number of men
= 40% x 5 u
= ⁴⁰₁₀₀ x 5 u
= 2 u

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

Number of men on Friday
= 5 u - 2 u
= 3 u

Number of women on Friday
= 12 u + 6 u
= 18 u

Number of adults on Friday
= 3 u + 18 u
= 21 u

On Friday
Adults : Children
21 : 7

(b)
Number of men and women on Thursday
= 5 u + 12 u
= 17 u

17 u = 816

1 u = 816 ÷ 17 = 48

Total number of adult visitors on Friday
= 21 u
= 21 x 48
= 1008

Answer(s): (a) 21 : 7; (b) 1008