Question

a water tank can be filled up by two pipes in 6hours nd 8hours respectively if both the pipes are opened at the same time when will be the empty ​

Answer 1

Explanation:

Pipe A is filling the tank at 1/6 (4/24) rate per hour.

Pipe B is filling the tank at 1/8 (3/24) rate per hour

The combined Filling rates of Pipe A & B = 7/24 per hour

Pipe C can empty the the tank at a rate of Minus 1/12 or 2/24 per hour.

Therefore the readjusted filling rate is 7/24 minus 2/24 per hour

= Readjusted Net Gain of ‘Filling’ is now only 5/24 per hour

divided by 5 = 4.8 hours or 4 hours & 48 minutes to fill the tank.