Two pipes A and B can fill a tank in 20 and 30 minutes respectively. If both the pipes are used together, then how long will it take to fill the tank?  Select:
A) 12 min	B) 15 min	C) 25 min	D) 50 min	E) 20 min
Part filled by A in 1 min. = 1/20   Part filled by B in 1 min. = 1/30   part filled by (A + B) in 1 min. = 1/20 + 1/30 = 1/12.   Both the pipes can fill the tank in 12 minutes.   12 minNSWER:12 min
<result>A</result>
Two pipes A and B can fill a tank in 20 and 30 minutes respectively. If both the pipes are used together, then how long will it take to fill the tank?