Question

two pipes can fill a tank in 12 and 18 hours respectively while the 3rd pipe can empty the tank in 24 hours if all the pipes are opened then how much time will be required to fill the tank

Answer 1

Answer:

10.2 hours

Step-by-step explanation:

Let Pipe A fill the tank in 12 hours. So A fills (1/12)th of the tank in 1 hour.

Let Pipe B fill the tank in 18 hours. So B fills (1/18)th of the tank in 1 hour.

Let Pipe C empty the tank in 24 hours. So C empties (1/24)th of the tank in 1 hour.

If all the three pipes are open together they fill

(1/12)+(1/18)-(1/24) = (6/72)+(4/72)-(3/72)

= 7/72 = 1/10.2 in 1 hour.

The tank will get filled in 10.2 hours.