Question

Two pipes A and B can fill a tank in 15 hours and 18 hours, respectively. Both pipes are opened simultaneously to fill the tank. In how many hours will the empty tank be filled?

• A. $$8\frac{2}{11}$$
• B. $$7\frac{2}{11}$$
• C. $$9\frac{2}{11}$$
• D. $$10\frac{2}{11}$$

Answer 1

Answer:

$$8\frac{2}{11}$$

Solution:

Given:

Pipe A can fill in 15 hours.

Pipe B can fill in 18 hours.

Calculation:

Tank filled by Pipe A in 1 hour

⇒ 1/15

Tank filled by Pipe B in 1 hour

⇒ 1/18

Tank filled by both Pipes in 1 hour

⇒ (1/15) + (1/18)

⇒ 11/90

Time taken By both pipes to fill the tank

⇒ 90/11

$8\frac{2}{11}hours$