A can complete a piece of work in 16 days and B can complete it in 20 days. They start working together. Two days before the completion of the work, A leaves. Work is completed in:
Q1. A can complete a piece of work in 16 days and B can complete it in 20 days. They start working together. Two days before the completion of the work, A leaves. Work is completed in:
Answer: 10 days
Explanation: Combined rate = 1/16+1/20 = 9/80 per day. In the last 2 days only B works, completing 2/20 = 1/10. Together they complete 9/10 in (9/10)÷(9/80) = 8 days, so total = 10 days.