Rahul can done a work in 5 days and meena can done a work in 10 days.In how many days that both are work together? Choose the correct option.
A) 3 / 10 B) 10 / 3 C) 1 / 3 D) 5 E) 6 / 3

Rationale: a ' s one day work = 1 / 5 b ' s one day work = 1 / 10 a + b = 1 / 5 + 1 / 10 = 10 + 5 / 50 = 10 / 3 days ans : option b
Answer: B