$A$ tap can fill the cistern in $8$ hours and another can empty it in $16$ hours. If both the taps are opened simultaneously,the time (in hours) to fill the tank is?

$A$ 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?

Two pipes can fill an empty tank separately in $24$ $minutes$ and $40$ $minutes$ respectively,and a third pipe can empty $30$ $gallons$ of water per $minute$. If all three pipes are opened,the empty tank becomes full in one $hour$. The capacity of the tank (in $gallons$) is:

Pipes $A$ and $B$ can fill a tank in $5$ $hours$ and $6$ $hours$ respectively. Pipe $C$ can empty it in $12$ $hours.$ If all the three pipes are opened together,then the tank will be filled in

$A$ reservoir is fitted with two pipes $A$ and $B$. Pipe $A$ can fill the reservoir $5$ $hours$ faster than pipe $B$. If both the pipes together fill the reservoir in $6$ $hours$,the reservoir will be filled by $A$ alone in:

$A$ pipe can fill a tank with water in $3 \, h$. Due to a leak at the bottom,it takes $3 \frac{1}{2} \, h$ to fill it. In what time (in $hours$) will the leak empty the fully filled tank?