PSLE
In a school, 40% of the members in Drama Club and 75% of the members in Reading Club are girls. Both clubs have the same number of boys. The Reading Club has 35 more girls than the Drama Club. How many girls are there altogether?

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

40% = ⁴⁰₁₀₀ = ²₅

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

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. 

3x15x1 of the members in Drama Club = 1x34x3 of the members in Reading Club
35of the members in Drama Club = 312 of the members in Reading Club

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

7 u = 35

1 u = 35 ÷ 7 = 5

Total number of girls
= 2 u + 9 u
= 11 u
= 11 x 5
= 55

Answer(s): 55