Student: If A takes x days to do a work then B takes 2x days to do the same work then with in how many day's A will alone complete this work ?
Options:
(A) 27
(B) 23
(C) 24
(D) 25
(E) 26.
Another student: Let's say, hmmm...
1/x+1/2x = 1/18 = > 3/2x = 1/18 = > x = 27 days. Hence, A alone can finish the work in 27 days. Final answer: (A).