Practice30 Create account

The tank in the figure holds 1,800 litres and is empty. Both pipes are opened together. How long does it take to fill?

Competition practicePipes & Cisterns

A120 min
B60 min
C40 min
D30 min

Step-by-Step Solution

Net inflow

= 45 - 15 = 30

L/min;

\frac{1800}{30} = 60

min. (30 min adds the outlet's flow; 40 min ignores it.)

Answer: B) 60 min

Master this topic in 30 minutes a day.

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

Practice 5 Similar Questions Free →

All Pipes & Cisterns practice questions

More Pipes & Cisterns practice

Pipe A can fill a tank in 18 minutes and pipe B can empty it in 27 minutes. If both are…Pipe A delivers 40% more water per hour than pipe B. Together they fill a tank in 7…A pipe fills a tank in 10 hours. After it has worked for 4 hours, a second pipe that…Tap A fills a tank in 20 minutes and tap B in 30 minutes. Both are opened together, but…All four pipes in the figure are opened together on the empty tank. How long does it…