A and B work together. A alone can complete the work in 30 days and B alone in 30 days. What percentage of the total daily work is contributed by A? MCQ with Answer and Explanation

Explanation:
Combined rate = 1/12 + 1/14. Required time = 6.46 days.

Explanation:
Total work = LCM(12, 15, 20) = 60 units. Efficiency of A = 5, B = 4, C = 3. Combined efficiency = 5 + 4 + 3 = 12 units/day. Time taken together = 60 / 12 = 5 days.

Explanation:
Let efficiency of B = 5, then efficiency of A = 4. Total work = Efficiency of A * Time of A = 4 * 15 = 60 units. Time taken by B = 60 / 5 = 12 days.