An inlet pipe can fill a swimming pool in 9 hours and an outlet pipe can empty the pool in 12 hours. through an error, both pipes are left open. how long will it take to fill te pool?

36 hours.

Step-by-step explanation:

Let x represent time taken by both pipes to fill the tank.

We have been given that an inlet pipe can fill a swimming pool in 9 hours. So part of pool filled by inlet pipe in one hour would be .

We are also told that an outlet pipe can empty the pool in 12 hours. The part of pool emptied by outlet pipe in one hour would be .

Sine the time taken by both pipes to fill the tank is x hours, so part of pool filled by both pipes in one hour would be .

We will get an equation using our given information as:

Let us solve for x.

Cross multiply:

Therefore, it will take 36 hours for both pipes to fill the tank.

your answer would be b

step-by-step explanation: