Question

Qus 7 : Two taps can fill a tank in 5 hours and 10 hours respectively . A third tap at the bottom can empty it in 20 hours. If all of them are opened together , how long will it take to fill the tank ?​

Answer 1

Answer: 4 hours

Step-by-step explanation:

Fill tap 1 === 5 hours = 1 tank

Fill tap in 1 hr == 1/5 tank

Fill tap 2 === 10 hours = 1 tank

Fill tap 2 in 1 hr === 1/10 tank

Empty pipe == 20 hours = 1 tank

In 1 hour = 1/20  tank

In 1 hour: part filed = 1/5 + 1/10 - 1/20 = {4+2-1)/20 = 5/20 = 1/4 parts.

1 tank in 4 hours