A man and a boy working together can finish a piece of work in 24 days. If for the last 6 days, the man alone works, then the work finished in 26 days. In how many days can the boy alone finish the work??

statement1: They can finish work in 24D

Statement2: They worked for 20D together, last 6D man worked alone. So 4D work done by Boy is equal to 2D work done by man.

So, their capacities might be 2units and 1unit for man and boy respectively.

For 24D, we have 24*3=72 units of work.

So for boy it will take 72 days to finish the work, as he do 1 unit of work on everyday

1/24 = 1/M + 1/B
5/6th of the work is completed in 20 days. Man compltes 1/6th work in 6 remaining days. So, man will take 36 days to complete work alone. M = 36. Subsituting, B = 72 days.