A and B can complete a work in 12 and 15 days, respectively. They work together for 4 days, then A leaves. How many more days will B take to complete the work?
Q1. A and B can complete a work in 12 and 15 days, respectively. They work together for 4 days, then A leaves. How many more days will B take to complete the work?
Answer: 6 days
Explanation: The combined work rate is 1/12 + 1/15 = 5/60 + 4/60 = 9/60. Work done in 4 days = 4 * (9/60) = 3/5. Remaining work = 1 - 3/5 = 2/5. B's work rate is 1/15. Time taken by B = (2/5) / (1/15) = 6 days.