A and B can finish a work 30 days if they work together. They worked together for 20 days and then B left. A finished the remaining work in another 20 days. In how many days A alone can finish the work?  Pick one:	A) 30	B) 60	C) 40	D) 20	E) 50
Amount of work done by A and 60 in 1 day = 1/30   Amount of work done by A and 60 in 20 days = 20 × (1/30) = 20/30 = 2/3   Remaining work – 1 – 2/3 = 1/3   A completes 1/3 work in 20 days   Amount of work A can do in 1 day = (1/3)/20 = 1/60   =&gt; A can complete the work in 60 days   Answer is 60.
<result>B</result>
A and B can finish a work 30 days if they work together. They worked together for 20 days and then B left. A finished the remaining work in another 20 days. In how many days A alone can finish the work?