SSC CHSL 15 Nov 2015 Shift 1 Paper

Percent of non members = 100 − (75 + 5 + 15) = 5%
Now, number of non members = 5% ≡ 40
⇒ $100\%=\frac{40}{5}\times 100=800$
Thus, total number of students = 800
Number of students who are members of both the clubs = $\frac{75}{100}\times 800$
= 75 × 8 = 600