PSLE
In a school, 30% of the members in Fitness Club and 75% of the members in Reading Club are boys. Both clubs have the same number of girls. The Fitness Club has 108 less boys than the Reading Club. How many members are there in Reading Club?

	Fitness Club		Reading Club
Types	Boys	Girls	Boys	Girls
Comparing the boys and the girls in each club	3x1	7x1	3x7	1x7
Comparing the girls in 2 clubs		1		1
	3 u	7 u	21 u	7 u

30% = ³⁰₁₀₀ = ³₁₀

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

75% = ⁷⁵₁₀₀ = ³₄

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

The number of girls in both clubs is the same. Make the numerators the same. LCM of 7 and 1 is 7. 

7x110x1 of the members in Fitness Club = 1x74x7 of the members in Reading Club
710of the members in Fitness Club = 728 of the members in Reading Club

Number of less boys in Fitness Club than Reading Club
= 21 u - 3 u
= 18 u

18 u = 108

1 u = 108 ÷ 18 = 6

Number of members in Reading Club
= 28 u
= 28 x 6
= 168

Answer(s): 168