PSLE
In a school, 30% of the members in Chess Club and 45% of the members in Literary Club are boys. Both clubs have the same number of girls. The Literary Club has 60 more boys than the Chess Club. How many boys are there altogether?

	Chess Club		Literary Club
Types	Boys	Girls	Boys	Girls
Comparing the boys and the girls in each club	3x11	7x11	9x7	11x7
Comparing the girls in 2 clubs		1		1
	33 u	77 u	63 u	77 u

30% = ³⁰₁₀₀ = ³₁₀

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

45% = ⁴⁵₁₀₀ = ⁹₂₀

Fraction of the members in Literary club that are girls
= 1 - ⁹₂₀
= ¹¹₂₀

The number of girls in both clubs is the same. Make the numerators the same. LCM of 7 and 11 is 77. 

7x1110x11 of the members in Chess Club = 11x720x7 of the members in Literary Club
77110of the members in Chess Club = 77140 of the members in Literary Club

Number of more boys in Literary Club than Chess Club
= 63 u - 33 u
= 30 u

30 u = 60

1 u = 60 ÷ 30 = 2

Total number of boys
= 33 u + 63 u
= 96 u
= 96 x 2
= 192

Answer(s): 192