Question

один насос за 4 часа наполняет 1/3 часть бассейна,а другая за 4 часа опорожняет 1/4 часть бассейна.За сколько часов наполнится бассейн,если оба насоса одновременно будут работать?

Answer 1

Ответ:

48часов

Пошаговое объяснение:

за 12 часа первый насос наполняет бассейн, а за 16ч второй насос опорожняет бассейн

1/12-1/16=1/48

отв 48

Answer 2

Problem Analysis

We are given that one pump can fill 1/3 of the pool in 4 hours, and another pump can empty 1/4 of the pool in 4 hours. We need to determine how long it will take to fill the entire pool if both pumps are working simultaneously.

Calculation

Let's assume that the pool has a total capacity of 1 unit.

In 4 hours, the first pump can fill 1/3 of the pool, which is equal to 1/3 * 1 = 1/3 unit.

In the same 4 hours, the second pump can empty 1/4 of the pool, which is equal to 1/4 * 1 = 1/4 unit.

To find the net amount of water added to the pool in 4 hours, we subtract the amount emptied from the amount filled: 1/3 - 1/4 = 1/12 unit.

Therefore, in 4 hours, the net amount of water added to the pool is 1/12 unit.

To find the time it takes to fill the entire pool, we can set up a proportion:

1/12 unit is filled in 4 hours. 1 unit will be filled in x hours.

Using the concept of cross-multiplication, we can solve for x:

(1/12) * x = 1 * 4 x/12 = 4 x = 4 * 12 x = 48

Therefore, it will take 48 hours to fill the entire pool if both pumps are working simultaneously.

Answer

If both pumps are working simultaneously, it will take 48 hours to fill the entire pool.