Question

Two taps a and b fill a tank separately in 24 minutes and 40 minutes respectively and a waste pipe c releases 30 litres per minute. If all the pipes are opened the tank is filled in an hour. The capacity of the tank is

Answer 1

Work Efficiency of Pipe One = 100/24 = 4.16% per minute

Work Efficiency of Pipe two = 100/40 = 2.5% %per minute.

Work Efficiency of third pipe which is doing a negative work = 30 gallons per minute

All three pipes can fill empty tank in 60 minute.

Work efficiency together = 100/60 = 1.66% per minute

Work Efficiency of third pipe = (1.66 - (4.16 +2.5)) = - 5

So, 5 = 30 gallons

1% = 30/5

Thus, 100% = (30*100)/5

So, Capacity of the tank = 600 gallons.