Pipes A and B can fill a tank in 10 and 6 hours respectively. Pipe C can empty it in 12 hours. If all the three pipes are opened together, then the tank will be filled in	Select the correct option.
A) 1 13/17 hours  B) 2 8/11 hours  C) 3 9/17 hours  D) 5 5/11 hours  E) None
Solution   Net part filled in 1 hour	= (1/10 + 1/6 -1/12)   = 11/60.   Therefore, the tank will be full in 60/11 hrs.	â€¹=â€º 5 5/11 hrs.   Answer 5 5/11 hours
<result>D</result>
Pipes A and B can fill a tank in 10 and 6 hours respectively. Pipe C can empty it in 12 hours. If all the three pipes are opened together, then the tank will be filled in