A can do a piece of work in 12 days and B in 15 days. They work together for 5 days and then B leaves. The days taken by A to finish the remaining work is: MCQ with Answer and Explanation

Total work = LCM(12, 15) = 60 units. Efficiency of A = 5, B = 4. In 5 days, work done = 5 * (5 + 4) = 45 units. Remaining work = 60 - 45 = 15 units. Time taken by A to finish remaining work = 15 / 5 = 3 days.