PSLE
In a school, 40% of the members in Reading Club and 60% of the members in Drama Club are girls. Both clubs have the same number of boys. The Drama Club has 40 more girls than the Reading Club. How many girls are there altogether?

	Reading Club		Drama Club
Types	Girls	Boys	Girls	Boys
Comparing the girls and the boys in each club	2x2	3x2	3x3	2x3
Comparing the boys in 2 clubs		1		1
	4 u	6 u	9 u	6 u

40% = ⁴⁰₁₀₀ = ²₅

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

60% = ⁶⁰₁₀₀ = ³₅

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

The number of boys in both clubs is the same. Make the numerators the same. LCM of 3 and 2 is 6. 

3x25x2 of the members in Reading Club = 2x35x3 of the members in Drama Club
610of the members in Reading Club = 615 of the members in Drama Club

Number of more girls in Drama Club than Reading Club
= 9 u - 4 u
= 5 u

5 u = 40

1 u = 40 ÷ 5 = 8

Total number of girls
= 4 u + 9 u
= 13 u
= 13 x 8
= 104

Answer(s): 104