Pipes A and B can fill a tank in 6 and 3 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) 2 2/5 hours.	B) 3 2/5 hours.	C) 1 1/5 hours.	D) 4 2/5 hours.	E) 2 1/5 hours.
Explanation:   Pipes A and B can fill the tank in 5 and 6 hours respectively. Therefore,   part filled by pipe A in 1 hour =1/6   part filled by pipe B in 1 hour = 1/3   Pipe C can empty the tank in 11 hours. Therefore,   part emptied by pipe C in 1 hour =1/12   Net part filled by Pipes A,B,C together in 1 hour   =1/6+1/3-1/12=5/12   i.e., the tank can be filled in 12//5= 
<gadget id="calculator">12//5</gadget>
<output>2</output>
2 2/5 hours.   2 2/5 hours.nswer: Option 2 2/5 hours.
<result>A</result>
Pipes A and B can fill a tank in 6 and 3 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: