Question

№1. Требуется смешать 3 части песка и 2 части цемента. Сколько цемента и песка нужно взять отдельно, чтобы получить 35 кг смеси? №2. На первой полке стояло в 3 раза больше книг, чем на второй. На двух полках вместе – 420 книг. Сколько книг стояло на каждой полке?

Answer 1

1)

2+3=5-частей всего

30/5=6-1 часть

2*6=12-цемента

3*6=18-песка

Ответ:12кг 18кг

- - - - - - - - - - - - - - - -

2)

х+3х=420

4х=420

х=105 - книг в-первой полке.

3х=3*105=315

Ответ: 105 и 315.

Answer 2

Task 1: Mixing Sand and Cement

To determine the amount of sand and cement needed separately to obtain a total mixture weight of 35 kg, we need to calculate the proportions based on the given ratio of 3 parts sand to 2 parts cement.

Let's assume that the weight of 1 part of sand is x kg, and the weight of 1 part of cement is y kg.

According to the given ratio, we have the following equation:

3x + 2y = 35

To solve this equation, we need another equation. However, we don't have any additional information about the weights of sand and cement. Therefore, we cannot determine the exact weights of sand and cement needed separately to obtain a total mixture weight of 35 kg.

Please provide additional information if available.

Task 2: Books on Shelves

Let's assume that the number of books on the second shelf is x.

According to the given information, the number of books on the first shelf is 3 times the number of books on the second shelf. Therefore, the number of books on the first shelf is 3x.

The total number of books on both shelves is 420. So we have the following equation:

x + 3x = 420

Simplifying the equation, we get:

4x = 420

Dividing both sides of the equation by 4, we find:

x = 105

Therefore, there were 105 books on the second shelf, and since the number of books on the first shelf is 3 times that, there were 315 books on the first shelf.

So, there were 105 books on the second shelf and 315 books on the first shelf.