A can do a piece of work in 32 days. When e had worked for 4 days, B joined him. If complete work was finished in 24 days in how many days B alone can finish that work?

Explanation:

A’s one day work = 1\32

A’s 4 days work = 1\32×4=1\8

Remaining part = 1−1\8=7\8

Since work was to be completed in 24 days, Remaining days=24-4=20 days

(A+B)’s 20 days work = 7\8

(A+B)’s one day’s work = 7\8×1\20=7\160

B’s one day’s work = 7\60−1\32=7−5\160=2\160=1\80

B can finish the work in 80 days.