$A$ tank has a leak which would empty it in $8$ $hrs$. $A$ tap is turned on which admits $6$ $litres$ a minute into the tank,and it is now emptied in $12$ $hrs$. How many litres does the tank hold?

$A$ leak in the bottom of a tank can empty the full tank in $8$ $hours$. An inlet pipe fills water at the rate of $6$ $litres$ a minute. When the tank is full,the inlet pipe is opened and due to the leak,the tank is empty in $12$ $hours$. How many litres does the tank hold?

In what time would a cistern be filled by three pipes whose diameters are $1 \text{ cm}$,$1 \frac{1}{3} \text{ cm}$,and $2 \text{ cm}$,running together,when the largest alone will fill it in $61 \text{ minutes}$,the amount of water flowing in by each pipe being proportional to the square of its diameter? (in $\text{minutes}$)

$2$ pipes $A$ and $B$ can fill a tank separately in $60$ $min$ and $70$ $min$ respectively. There is a third pipe attached to the bottom of the tank to empty it. The tank is filled in $60$ $min$ when all three pipes are opened. In how much time $(min)$ will the third pipe alone take to empty the tank?

Three pipes $A, B$ and $C$ can fill a cistern in $10$ $hours$,$12$ $hours$ and $15$ $hours$ respectively. First $A$ was opened. After $1$ $hour$,$B$ was opened and after $2$ $hours$ from the start of $A$,$C$ was also opened. Find the time in which the cistern is just full.

Two pipes $A$ and $B$ can fill a water tank in $10$ and $12$ $min,$ respectively,and a third pipe $C$ can empty it at the rate of $6$ $gallons$ per $min.$ If $A, B,$ and $C$ are opened together,they fill the tank in $20$ $min.$ What is the capacity (in $gallons$) of the tank?