Question

Pipes A and B can fill a tank in 16 hours and 24 hours, respectively, whereas pipe C can empty the full tank in 40 hours. All three pipes are opened together, but pipe C is closed after 10 hours. After how many hours will the remaining part of the tank be filled ?

• A. 5 hours
• B. $$2\frac{1}{2}hours$$
• C. 2hours
• D. $$5\frac{1}{2}hours$$

Answer 1

Answer:

C. 2hours

Solution:

Calculation:

Pipe A, B, and C can fill in 1 hour

⇒ 15 + 10 - 6

⇒ 19

(A + B + C) can fill in 10 hours

⇒ 19 × 10

⇒ 190

Remaining empty tank

⇒ 240 - 190

⇒ 50

Remaining empty tank filled by A and B

⇒ 50/25

⇒ 2 hours

∴ Time taken to fill remaining tank is 2 hours.