Question

In a combined test in English and Physics; 36% candidates failed in English; 28% failed in Physics and 12% in both; find:
the total number of candidates appeared, if 208 candidates have failed.

Answer 1

Candidates failed only in English
= 36% - 12%
= 24%
Candidates failed only in Physics
= 28% - 12%
 =16%
Candidates failed in both subjects = 12%
Total failed candidates 
= 24% + 16% + 12%
= 52%
If failed candidates are 52, then total candidates appeared = 100
If failed candidates is 1, then total candidates appeared = `(100)/(52)`
if failed candidates are 208, the total candidates appeared
= `(100)/(52) xx 208`
= 100 x 4
= 400