Q12. Pipe A can fill a tank in 10 hours, and pipe B can empty it in 15 hours. If both pipes are opened together for 4 hours and then pipe A is closed, how long will it take for pipe B to empty the water in the tank?Mathematics — Word Problems — Question 12 of 38A. 2 hoursB. 6 hoursC. 9 hoursD. 15 hoursPractice more Mathematics MCQs for entrance exam preparation on Examora.io.← Previous Question Next Question →