Question

бассейн наполняется первой трубой за 4ч , а через вторую трубу опорожнен за 5 час. Через сколько часов будет наполнен весь бассейн, если одновременно открыть обе трубы

Answer 1

Problem Analysis

We are given that a pool is being filled by two pipes. The first pipe can fill the pool in 4 hours, while the second pipe can empty the pool in 5 hours. We need to determine how long it will take to fill the entire pool if both pipes are opened simultaneously.

Solution

To solve this problem, we can calculate the rates at which each pipe fills or empties the pool. Then, we can find the combined rate at which the pool is being filled or emptied when both pipes are open. Finally, we can use this combined rate to calculate the time it takes to fill the entire pool.

Let's start by calculating the rates at which each pipe fills or empties the pool.

The first pipe fills the pool in 4 hours, so its filling rate is 1/4 of the pool per hour. Similarly, the second pipe empties the pool in 5 hours, so its emptying rate is 1/5 of the pool per hour.

When both pipes are open, the combined rate at which the pool is being filled or emptied is the difference between the filling rate of the first pipe and the emptying rate of the second pipe. Therefore, the combined rate is (1/4) - (1/5) of the pool per hour.

To find the time it takes to fill the entire pool, we can divide the pool's capacity by the combined rate. However, since the question does not provide the pool's capacity, we cannot determine the exact time it takes to fill the entire pool.

Please provide the capacity of the pool, and I will be able to calculate the time it takes to fill the pool when both pipes are open.