A can finish a work in 18 days and B can do the same work in 15 days. B worked for 10 days and left the job. In how many days can A alone finish the remaining work? MCQ with Answer and Explanation

Total work = LCM(18, 15) = 90 units. Efficiency of A = 5, B = 6. B works for 10 days: work done = 10 * 6 = 60 units. Remaining work = 90 - 60 = 30 units. Time taken by A to finish the remaining work = 30 / 5 = 6 days.