Rajesh and Bhupesh can complete a piece of work in 20 days and Bhupesh alone in 25 days. In how many days can Rajesh alone complete the work?

ATQ, Rajesh and Bhupesh together finish the work in 20 days, which means their combined work rate is 1/20 of the work per day. Bhupesh alone finishes the work in 25 days, so his work rate is 1/25 of the work per day. To find Rajesh’s work rate, we subtract Bhupesh’s work rate from their combined rate: Combined rate - Bhupesh’s rate = Rajesh’s rate 1/20 - 1/25 = 5/100 - 4/100 = 1/100 Rajesh’s work rate is thus 1/100 of the work per day. To find out how long he takes to do the entire work, we take the reciprocal of his work rate: Rajesh can complete the work in 100 days.