Question

2) Две трубы наполняют бассейн за 3 часа, а одна первая труба наполняет бассейн за 7 часов. За сколько часов наполняет бассейн одна вторая труба?​

Answer 1

Ответ:

Пошаговое объяснение:

1) 1 : 3 = 1/3 - производительность двух труб

2) 1 : 7 = 1/7 (часть) - бассейна

заполняет за 1 час 1 труба

3) 1/3 - 1/7 = 7/21 - 3/21 = 4/21 (часть) - заполняет за 1 час 2 труба

4) 1 : 4/21 = 1 * 21/4 = 21/4 = 5. 1/4 (часа) - заполнит весь бассейн вторая труба работая в одиночку

Ответ: за 5. 1/4 часа

Answer 2

Problem Analysis

We are given that two pipes can fill a pool in 3 hours, and one of the pipes can fill the pool in 7 hours. We need to determine how long it would take for the second pipe to fill the pool on its own.

Solution

Let's assume that the first pipe can fill the pool at a rate of 1 pool per 7 hours. This means that in 1 hour, the first pipe can fill 1/7th of the pool.

Since both pipes together can fill the pool in 3 hours, we can calculate their combined rate of filling the pool. If we let x represent the rate at which the second pipe fills the pool, we can set up the following equation:

1/7 + 1/x = 1/3

To solve for x, we can multiply both sides of the equation by 21x (the least common multiple of 7 and 3) to eliminate the fractions:

3x + 21 = 7x

Rearranging the equation, we get:

4x = 21

Dividing both sides by 4, we find:

x = 21/4 = 5.25

Therefore, the second pipe can fill the pool on its own in 5.25 hours.

Answer

The second pipe can fill the pool on its own in 5.25 hours.