A and B together can complete a work in 12 days. A alone can complete it in 20 days. If B does the work only for half a day daily, then in how many days A and B together will complete the work?	Pick one:	A) 10 days	B) 11 days	C) 15 days	D) 20 days	E) None of these
B's 1 day's work=(1/12-1/20)=2/60=1/30   Now, (A+B)'s 1 day's work=(1/20+1/60)=4/60=1/15   So, A and B together will complete the work in 15 days.   15 daysorrect Option: 15 days
<result>C</result>
A and B together can complete a work in 12 days. A alone can complete it in 20 days. If B does the work only for half a day daily, then in how many days A and B together will complete the work?