A and B can complete a piece of work in 24 days and 30 days respectively. Working together, what fraction of the work can they complete in 4 days? MCQ with Answer and Explanation

Explanation:
Total work = LCM(9, 12) = 36 units. Efficiency of A = 4, B = 3. In 2 days (A + B), work done = 4 + 3 = 7 units. In 10 days (5 pairs of 2 days), work done = 7 * 5 = 35 units. Remaining work = 36 - 35 = 1 unit. On the 11th day, it is A's turn. Time taken by A to complete 1 unit = 1/4 day. Total time = 10 + 1/4 = 10(1/4) days.

Explanation:
Combined rate = 1/10 + 1/20. Time = 1 ÷ combined rate = 6.67 days.

Explanation:
Total work = LCM(10, 15, 30) = 30 units. Efficiency of A = 3, B = 2, C = 1. In a 3-day cycle (A on day 1, B on day 2, C on day 3), work completed = 3 + 2 + 1 = 6 units. Number of cycles required = 30 / 6 = 5 cycles. Total days = 5 * 3 = 15 days.