A can do a piece of work in 12 days. He worked for 15 days and then B completed the remaining work in 10 days. Both of them together will finish it in. Answers
A) 11 1/2 days	B) 15 1/2 days	C) 15 1/2 days	D) 16 1/2 days	E) 12 1/2 days
12 1/2 days   12 1/2 days   15/25 + 10/x = 1 =&gt; x = 25   1/25 + 1/25 = 2/25   25/2 = 12 1/2 days
<result>E</result>
A can do a piece of work in 12 days. He worked for 15 days and then B completed the remaining work in 10 days. Both of them together will finish it in.