In an examination, 35% candidates failed in one subject and 42% failed in another subject while 15% failed in both the subjects. If 2500 candidates appeared at the examination, how many passed in either subject but not in both ?

Answer: Option B

Failed in 1^st subject = $$\frac{35}{100}$$ × 2500 = 875
Failed in 2^nd subject = $$\frac{42}{100}$$ × 2500 = 1050
Failed in both = $$\frac{15}{100}$$ × 2500 = 375
Failed in 1^st subject only = (875 - 375) = 500
Failed in 2^nd subject only = (1050 - 375) = 675
∴ Passed in 2^nd only + Passed in 1^st only
= (675 + 500)
= 1175