Two inlet pipes can fill a cistern in $10$ $hours$ and $12$ $hours$ respectively,and an outlet pipe can empty $80$ $gallons$ of water per hour. All three pipes working together can fill the empty cistern in $20$ $hours$. What is the capacity (in $gallons$) of the tank?

Two pipes can fill a cistern in $14$ $h$ and $16$ $h$,respectively. The pipes are opened simultaneously and it is found that due to leakage in the bottom,it took $92$ $min$ more to fill the cistern. When the cistern is full,in what time will the leak empty it?

If pipe $P$ can fill a tank in $p$ hours and pipe $Q$ can empty the same tank in $q$ hours (where $q > p$),and both pipes are opened simultaneously,in how many hours $(r)$ will the tank be filled?

$A$ tap drips at a rate of $1$ drop/sec. If $600$ drops make $100 \text{ ml}$,the number of litres wasted in $300$ days is:

$A$ pump can fill a tank with water in $2$ $hours$. Because of a leak,it took $2 \frac{1}{3}$ $hours$ to fill the tank. The leak can drain all the water of the tank in (in $hours$)?

Two pipes $A$ and $B$ can separately fill a cistern in $60$ $minutes$ and $75$ $minutes$ respectively. There is a third pipe in the bottom of the cistern to empty it. If all the three pipes are simultaneously opened,then the cistern is full in $50$ $minutes$. In how much time (in $minutes$) can the third pipe alone empty the cistern?