Question: A and B complete a work in 9 days. A alone can do it in 18 days. If both together can do the work in how many days?
Options:
(A) 6 days
(B) 8 days
(C) 5 days
(D) 7 days
(E) 15 days Random thoughts:
1/9 + 1/18 = 1/6
6/1 = 6 days The final answer: (A).