A and B can do a piece of work in 24 days and 13 days respectively. A works alone for 19 days and then leaves. How many days will B take to complete the remaining work?

Correct option is B

A’s one day work = 1/24 A’s 19 days work = 19/24 Remaining work = 1 − 19/24 = 5/24 B’s one day work = 1/13 Time taken by B to complete the remaining work = = (5/24) ÷ (1/13) = (5/24) × 13 = 65/24 = 2 17/24 days
Explanation of options: (a) ✘ 2 20/24 overestimates the remaining work. (b) ✔ 65/24 days = 2 17/24 — exactly correct. (c) ✘ 2 15/24 is less than the actual result. (d) ✘ 2 14/24 is not the correct result — incorrect calculation.