A and B can together finish a work 30 days. They worked together for 20 days and then B left. After another 20 days, A finished the remaining work. In how many days A alone can finish the work?
Pick one
A) 40  B) 50  C) 54  D) 60  E) 64
(A + B)'s 20 day's work =	(1/30 x 20	)	=	2/3	.   Remaining work =	(1 -	2/3 )	=	1/3	.   Now,	1/3	work is done by A in 20 days.   Therefore, the whole work will be done by A in (20 x 3) = 60 days.   Answer : 60
<result>D</result>
A and B can together finish a work 30 days. They worked together for 20 days and then B left. After another 20 days, A finished the remaining work. In how many days A alone can finish the work?