A can complete some work in 35 days and B can complete the same work in 15 days. They worked together for 8 days, then B left the work. In how many days will A alone complete 60% of the remaining work?
A
Correct answer
Explanation
A's rate is 1/35 per day, B's rate is 1/15 per day. Combined rate = 2/21 per day. Work done in 8 days = 16/21. Remaining work = 5/21. 60% of remaining = 3/21 = 1/7. Time for A to complete 1/7 = (1/7)/(1/35) = 5 days. The key is to first find the combined work rate, then calculate the remaining portion after 8 days.