Practice30 Create account

The tank in the picture is already half full. Inlet A and outlet C are now both opened. How many more hours will it take for the tank to become full?

Class 8Pipes and CisternsDirect and Inverse Proportions

A30 h
B6 h
C15 h
D7 1/2 h

Step-by-Step Solution

Net rate

= \frac{1}{10} - \frac{1}{15} = \frac{1}{30}

of the tank per hour. Half the tank is still empty, so time

= \frac{1}{2} \div \frac{1}{30} = 15

h.

Answer: C) 15 h

Master this chapter in 30 minutes a day.

Don't just memorise the answer — build a daily practice habit.

Practice 5 Similar Questions Free →

All Pipes and Cisterns practice questions

More Class 8 Pipes and Cisterns practice

Tap A alone fills the tank in 6 hours. Because of the leak in the bottom, the tank…The tank shown has three pipes. One morning only two of them were open, and the empty…The tank is two-thirds full when inlet A and outlet C are both opened, as shown. What…Both taps on the empty tank are opened together. After 3 hours tap A is turned off and…A pipe can fill a tank in 12 hours. Another pipe can empty it in 18 hours. If both are…