One inlet pipe can fill an empty pool in 4 hours, and a drain can empty the pool in 8 hours. how long will it take the pipe to fill the pool if the drain is left open?

Given that one inlet pipe can fill an empty pool in 4 hours. The outlet pipe can empty the pool in 8 hours. We know that rate x time = work done.

Rate = work done / time

Rate of inlet pipe = ¼ hours.

Rate of outlet pipe = 1/8 hours

Here 1 represent the work completed.

Let x be the time taken to fill the pool by the inlet pipe if the drain is left.

Work done by inlet pipe - work done by outlet pipe = 1 work completed.

x/4 - x/8 = 1.

To solve the rational equation, first we clear the fractions by multiplying it with LCD (4,8) = 8 to each item.

8 (x/4) - 8 (x/8) = 8 (1)

2x - x = 8

X = 8

Time taken for the pipe to fill the pool if the drain is left open = 8 hours