PSLE
In a school, 70% of the members in Fitness Club and 75% of the members in Reading Club are girls. Both clubs have the same number of boys. The Reading Club has 6 more girls than the Fitness Club. How many girls are there altogether?

	Fitness Club		Reading Club
Types	Girls	Boys	Girls	Boys
Comparing the girls and the boys in each club	7x1	3x1	3x3	1x3
Comparing the boys in 2 clubs		1		1
	7 u	3 u	9 u	3 u

70% = ⁷⁰₁₀₀ = ⁷₁₀

Fraction of the members in Fitness Club that are boys
= 1 - ⁷₁₀
= ³₁₀

75% = ⁷⁵₁₀₀ = ³₄

Fraction of the members in Reading club that are boys
= 1 - ³₄
= ¹₄

The number of boys in both clubs is the same. Make the numerators the same. LCM of 3 and 1 is 3. 

3x110x1 of the members in Fitness Club = 1x34x3 of the members in Reading Club
310of the members in Fitness Club = 312 of the members in Reading Club

Number of more girls in Reading Club than Fitness Club
= 9 u - 7 u
= 2 u

2 u = 6

1 u = 6 ÷ 2 = 3

Total number of girls
= 7 u + 9 u
= 16 u
= 16 x 3
= 48

Answer(s): 48