PSLE
In a school, 60% of the members in Drama Club and 80% of the members in Reading Club are girls. Both clubs have the same number of boys. The Drama Club has 55 less girls than the Reading Club. How many members are there in Reading Club?

	Drama Club		Reading Club
Types	Girls	Boys	Girls	Boys
Comparing the girls and the boys in each club	3x1	2x1	4x2	1x2
Comparing the boys in 2 clubs		1		1
	3 u	2 u	8 u	2 u

60% = ⁶⁰₁₀₀ = ³₅

Fraction of the members in Drama Club that are boys
= 1 - ³₅
= ²₅

80% = ⁸⁰₁₀₀ = ⁴₅

Fraction of the members in Reading club that are boys
= 1 - ⁴₅
= ¹₅

The number of boys in both clubs is the same. Make the numerators the same. LCM of 2 and 1 is 2. 

2x15x1 of the members in Drama Club = 1x25x2 of the members in Reading Club
25of the members in Drama Club = 210 of the members in Reading Club

Number of less girls in Drama Club than Reading Club
= 8 u - 3 u
= 5 u

5 u = 55

1 u = 55 ÷ 5 = 11

Number of members in Reading Club
= 10 u
= 10 x 11
= 110

Answer(s): 110