ibps-so 2019 · Question 287 of 300

The overhead tank of the same premises is served by an inlet and by an outlet, both of which were found open one morning. One pipe can fill an empty cistern in 20 minutes, while a second pipe can empty the full cistern in 30 minutes. If both the pipes are opened together upon the empty cistern, in how long will the cistern be filled?

1. A45 minutes
2. B50 minutes
3. C55 minutes
4. D75 minutes
5. E60 minutesCorrect