A can complete a work in 23 days and B can complete the same work in 28 days. If they work together, in how many days will the work be completed? MCQ with Answer and Explanation

Explanation:
Total work = 19 × 29 = 551 man-days. Required days = 551/23 = 23.96 days.

Explanation:
Total work = 8 × 18 = 144 man-days. Required days = 144/12 = 12.0 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.