A pipe can fill a tank in 6 hours and another pipe can empty the tank in 12 hours. If both the pipes are opened at the same time, the tank can be filled in

Question	A pipe can fill a tank in 6 hours and another pipe can empty the tank in 12 hours. If both the pipes are opened at the same time, the tank can be filled in
Type	multiple_choice
Option	10 hours	incorrect
Option	12 hours	correct
Option	14 hours	incorrect
Option	16 hours	incorrect

Part of the tank filled in one hour = 1/6

Part of the tank emptied in one hour = 1/12

= 1/6 – 1/12

1/12

Part of the tank can be filled in one hour.

∴ The tank will be filled completely in 12 hours.

Solution 2:Apply formula; = 

X = 6 hours and Y = 12 hours

∴ 

= 12 hours