Question

A is thrice as good a workman as B and takes 10days less to do a piece of work than B takes B alone can do the whole work

Answer 1

Ratio of times taken by A and B = 1:3
Means B will take 3 times which A will do in 1 time

If difference of time is 2 days, B takes 3 days
If difference of time is 10 days, B takes (3/2) * 10 =15 days