A work can be finished in 13 days by ten women. The same work can be finished in fifteen days by ten men. The ratio between the capacity of a man and a woman is	Pick one.
A) 14 : 13  B) 13 : 15  C) 12 : 13  D) 13 : 12  E) 14 : 15

Rationale: work done by 10 women in 1 day = 1 / 13 work done by 1 woman in 1 day = 1 / ( 13 ã — 10 ) work done by 16 men in 1 day = 1 / 15 work done by 1 man in 1 day = 1 / ( 15 ã — 10 ) ratio of the capacity of a man and woman = 1 / ( 15 ã — 10 ) : 1 / ( 13 ã — 10 ) = 1 / 15 : 1 / 13 = 1 / 15 : 1 / 13 = 13 : 15 answer is b .
Answer: B