$A$ pipe can empty a cistern in $27$ $hours$. Find the time (in $hours$) in which $\frac{2}{3}$ part of the cistern will be emptied?

Having the same capacity,$9$ taps fill up a water tank in $20$ minutes. How many taps of the same capacity are required to fill up the same water tank in $15$ minutes?

$A$ tap can fill a tank in $25$ $minutes$ and another can empty it in $50$ $minutes$. Find out whether the tank will be filled up or emptied and in how many $minutes$?

An outlet pipe can empty a cistern in $3$ $h$. In what time (in $h$) will the pipe empty two-third part of the cistern?

$A$ tank has two pipes. The first pipe can fill it in $45$ minutes and the second can empty it in $1$ hour. In what time will the empty tank be filled if the pipes are opened one at a time in alternate minutes?

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