Pipes A and B can fill a tank in 5 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:
1$ \dfrac{13}{17} $hours
2$ \dfrac{8}{11} $hours
3$ \dfrac{9}{17} $hours
4$ \dfrac{1}{2} $hours
Explanation:
Net part filled in 1 hour$ \left(\dfrac{1}{5} +\dfrac{1}{6} -\dfrac{1}{12} \right) $=$ \dfrac{17}{60} $.
$\therefore$ The tank will be full in$ \dfrac{60}{17} $hours i.e., 3$ \dfrac{9}{17} $hours.