A can complete a work in 21 days and B can complete the same work in 26 days. If they work together, in how many days will the work be completed? MCQ with Answer and Explanation

Explanation:
Wages are distributed in the ratio of their efficiencies. Ratio of time taken = 12 : 15 : 20. Ratio of efficiencies = 1/12 : 1/15 : 1/20. Multiplying by LCM (60), we get 5 : 4 : 3.

Explanation:
Combined 1-day work = 1/4. A's 1-day work = 1/12. B's 1-day work = 1/4 - 1/12 = 2/12 = 1/6. Therefore, B alone can complete the work in 6 days.

Explanation:
Remaining work = (1 - 5*(1/10+1/20))×100 = 25.0%.