Question

Три школьника купили карандаши. Один отдал за эту покупку 21 рубль, другой 18 рублей, а третий 15 рублей. Первый школьник получил на два карандаша больше, чем третий. Сколько карандашей купил каждый школьник?

Answer 1

21-15=6-руб.за 2 кар.
6:2=3-1 кар.
21:3=7 -1-ый
18:3=6 -2-ой
15:3=5 -3-ий

Answer 2

Problem Analysis

We are given that three schoolchildren bought pencils, and we need to determine how many pencils each child bought. We are also given the amounts each child paid for the pencils, as well as the information that the first child received two more pencils than the third child.

Solution

Let's assume that the third child bought x pencils. According to the given information, the first child received two more pencils than the third child, so the first child bought x + 2 pencils.

We are also given the amounts each child paid for the pencils. The first child paid 21 rubles, the second child paid 18 rubles, and the third child paid 15 rubles.

To find the number of pencils each child bought, we need to solve the following equations:

1. The first child paid 21 rubles for x + 2 pencils. 2. The second child paid 18 rubles for y pencils. 3. The third child paid 15 rubles for x pencils.

We can set up the following equation based on the given information:

21 = (x + 2) * p1 18 = y * p2 15 = x * p3

Where p1, p2, and p3 represent the price per pencil for each child.

To solve this system of equations, we need to know the values of p1, p2, and p3. Unfortunately, the given information does not provide these values. Therefore, we cannot determine the exact number of pencils each child bought without additional information.

Please provide the values of p1, p2, and p3, or any other relevant information, so that we can solve the problem accurately.