PSLE
On Thursday, the number of children to men to women visiting a theme park was 1 : 10 : 10. On Friday, the number of children visiting the theme park remained the same. However, the number of men decreased by 30% and the number of women increased by 30%.

1. What was the ratio of the number of adults to children visiting the theme park on Friday?
2. On Thursday, 780 men and women visited the theme park. What was the total number of adult visitors at the theme park on Friday?

	Children	Men	Women
Before	1 u	10 u	10 u
Change		- 3 u	+ 3 u
After	1 u	7 u	13 u

(a)
Increase in the number of men
= 30% x 10 u
= ³⁰₁₀₀ x 10 u
= 3 u

Decrease in the number of women
= 30% x 10 u
= ³⁰₁₀₀ x 10 u
= 3 u

Number of men on Friday
= 10 u - 3 u
= 7 u

Number of women on Friday
= 10 u + 3 u
= 13 u

Number of adults on Friday
= 7 u + 13 u
= 20 u

On Friday
Adults : Children
20 : 1

(b)
Number of men and women on Thursday
= 10 u + 10 u
= 20 u

20 u = 780

1 u = 780 ÷ 20 = 39

Total number of adult visitors on Friday
= 20 u
= 20 x 39
= 780

Answer(s): (a) 20 : 1; (b) 780