A and B can complete a piece of work in 12 days and 18

Solution

A's work rate = 1/12 (work done in one day) B's work rate = 1/18 Combined Work Rate: Work done by A and B together in one day = (1/12) + (1/18) = (3/36) + (2/36) = 5/36 Work Done in 6 Days Together: Work done in 6 days = 6 × (5/36) = 30/36 = 5/6 of the work. Remaining work = 1 - 5/6 = 1/6 of the work. Time Taken by B to Complete the Remaining Work: B can complete the remaining work in: Time = Remaining work / B's work rate = (1/6) / (1/18) = (1/6) × (18/1) = 3 days. Correct Answer: d