Question

A tank two outlets a and b which together take 6 hours to empty a full tank when they are opened simultaneously. The tank was initially half-full and both the outlets were opened. After an hour, an inlet pipe x was also opened. If the inlet alone can fill an empty tank in 4 hours, how much time will it now take to fill the tank completel

Answer 1

Answer:

It takes 8 hours to fill the tank completely.

Step-by-step explanation:

Both a and b opened together will empty the tank in in 6 hours.

Therefore, the amount emptied in 1 hour will be :

= 1/6 of the tank.

The tank was half full therefore the amount emptied will be :

= 1/2 - 1/6 = 1/3

The remaining part of the tank to be filled = 3/3 - 1/3 = 2/3

In 1 hour the inlet tap fills : = 1/4 of the tank.

In 1 hr when all the taps are opened the amount retained in the tank :

= 1/4 - 1/6 = 1/12

We need to work out the time it takes to fill 2/3 of the tank :

2/3 × 12/1 = 8 hours

Answer 2

Answer:

let time reqired x hr

ATQ, x-1/4 -x/6 equal 1/2

so, x equal 9