Question

A can do a job in 6 days while A and B can do it together in 2 days . how many days will be taken by B to do the job alone

Answer 1

Explanation:

A can do in 1 day 1/6 of the work.

B can do in 1 day 1/x of the work.

together, in 2 days, they do the whole work (1) :

2×1/6 + 2/x = 1

2x/6 + 2 = x

x/3 + 2 = x

2 = x - x/3 = 3x/3 - x/3 = 2x/3

6 = 2x

x = 3

so, B can do in 1 day 1/3 of the work.

that means it takes B 3 days to do the whole work alone.