Three taps $A, B$ and $C$ fill a tank in $20$ min,$15$ min and $12$ min,respectively. If all the taps are opened simultaneously,how long will they take to fill $40 \%$ of the tank (in $min$)?

Three taps are fitted in a cistern. The empty cistern is filled by the first and the second taps in $3 \, h$ 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?

There are two inlets $A$ and $B$ connected to a tank. $A$ and $B$ can fill the tank in $16 \text{ h}$ and $10 \text{ h}$,respectively. If both the pipes are opened alternately for $1 \text{ h}$,starting with $A$,then how much time will the tank take to be filled?

$A$ swimming pool is fitted with three pipes. The first two pipes working simultaneously fill the pool in the same time as the third pipe alone. The second pipe alone fills the pool $5$ hours faster than the first pipe and $4$ hours slower than the third pipe. In what time (in hours) will the second and third pipes together fill the pool?

$A$ tap takes $36$ hours extra to fill a tank due to a leakage equivalent to half of its inflow. In how many hours can the inlet pipe alone fill the tank?

If a pipe fills a tank in $6 \ h$,then what part of the tank will the pipe fill in $1 \ h$?