$A$ cistern is normally filled in $8$ $hours$,but it takes $2$ $hours$ longer to fill because of a leak at its bottom. If the cistern is full,the leak will empty it in (in $hours$):

Two pipes $A$ and $B$ can fill a cistern in $20$ $minutes$ and $25$ $minutes$ respectively. Both are opened together,but after $5$ $minutes,$ $B$ is turned off. How much time (in $minutes$) longer will the cistern take to fill?

$A$ tank can be filled with water by two pipes $A$ and $B$ together in $36$ minutes. If the pipe $B$ was closed after $30$ minutes,the tank is filled in $40$ minutes. The pipe $B$ can alone fill the tank in?

$A$ cistern has two taps which fill it in $12$ $minutes$ and $15$ $minutes,$ respectively. There is also a waste pipe in the cistern. When all the pipes are opened, the empty cistern is full in $20$ $minutes.$ How long will the waste pipe take to empty a full cistern?

One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill the tank in $36$ minutes,then the slower pipe alone will be able to fill the tank in (in minutes):

Three taps are fitted to a cistern. The empty cistern is filled by the first and second taps in $3$ and $4 \, h$,respectively. The full cistern is emptied by the third tap in $5 \, h$. If all three taps are opened simultaneously,the empty cistern will be filled up in?