A can do a piece of work in 10 days, B can do it in 15 days. They work together for 5 days, then B leaves. How many more days will A take to finish the work?
Q1. A can do a piece of work in 10 days, B can do it in 15 days. They work together for 5 days, then B leaves. How many more days will A take to finish the work?
Answer: 2 days
Explanation: A's rate = 1/10, B's rate = 1/15. Together, they complete (1/10 + 1/15) * 5 = 5/6 of the work in 5 days. Remaining work = 1/6, A will take (1/6) / (1/10) = 5/3 = 1.67 days, so 2 more days.