Question

В двух аамбарах сложено зерно. Во втором зерна в 3 раза меньше,чем в первом. После того как из первого амбара взяли 20 т. зерна, а во второй добавили 20 т., оказалось, что масса зерна во втором амбаре равна 5/7 массы зерна, оставшегося в первом. Сколько тонн зерна было первоначально во втором амбаре? ​

Answer 1

Ответ:

Как то так
Объяснение:

Answer 2

Problem Analysis

We are given two barns, and the amount of grain in the second barn is three times less than the amount in the first barn. After taking 20 tons of grain from the first barn and adding 20 tons to the second barn, it is found that the mass of grain in the second barn is equal to 5/7 of the mass of grain remaining in the first barn. We need to determine the initial amount of grain in the second barn.

Solution

Let's assume the initial amount of grain in the first barn is x tons. Therefore, the initial amount of grain in the second barn is x/3 tons.

After taking 20 tons of grain from the first barn, the remaining amount of grain in the first barn is x - 20 tons.

After adding 20 tons of grain to the second barn, the amount of grain in the second barn becomes (x/3) + 20 tons.

According to the given information, the mass of grain in the second barn is equal to 5/7 of the mass of grain remaining in the first barn. Therefore, we can write the equation:

(x/3) + 20 = (5/7)(x - 20)

To solve this equation, we can follow these steps:

1. Multiply both sides of the equation by 21 to eliminate the denominators:

21[(x/3) + 20] = 21[(5/7)(x - 20)]

Simplifying:

7x + 420 = 15(x - 20)

2. Expand the equation:

7x + 420 = 15x - 300

3. Move all the terms with x to one side and the constant terms to the other side:

7x - 15x = -300 - 420

Simplifying:

-8x = -720

4. Divide both sides of the equation by -8 to solve for x:

x = (-720)/(-8) = 90

Therefore, the initial amount of grain in the second barn was 90/3 = 30 tons.

Answer

The initial amount of grain in the second barn was 30 tons.