Ravi can do a piece of work in 20 days while Prakash can do it in 40 days. In how many days will they finish it together?\nOptions:\n(A) 5 7/9 days\n(B) 6 7/9 days\n(C) 5 1/9 days\n(D) 5 7/2 days\n(E) 4 7/9 days OK. Let's think. Some random thoughts first:
User
1/20 + 1/40 = 3/40\n40/7 = 5 7/9 days The answer: (A).
Assistant