Question

Помогите пожалуйста решить задачу У брата и сестры вместе было 360 руб. Брат на все свои деньги купил 9 одинаковых по цене общих тетрадей, а сестра на свои - 3 такие же тетради. Сколько денег было у сестры и сколько у брата.

Answer 1

1)360:(9+3)=30(р.)- стоимость одной тетради
2)30×9=270(р.)-было у брата
3)30×3=90(р.)-было у сестры
Ответ: 90 рублей было у сестры, 270 рублей у брата.

Answer 2

1)3+9=12 тетрадей купили всего
2)360:12=30 рублей за 1 тетрадей
3)30*9=270 рублей у брата
4)30*3=90 рублей у сестры

Answer 3

Problem Analysis

We are given that the brother and sister together had 360 rubles. The brother used all his money to buy 9 identical notebooks, while the sister used her money to buy 3 identical notebooks. We need to determine how much money the sister had and how much money the brother had.

Solution

Let's assume that the brother had x rubles and the sister had y rubles.

According to the problem, the brother used all his money to buy 9 identical notebooks. This means that the cost of each notebook is x/9 rubles.

Similarly, the sister used all her money to buy 3 identical notebooks. This means that the cost of each notebook is y/3 rubles.

Since the cost of each notebook is the same, we can set up the following equation:

(x/9) * 9 + (y/3) * 3 = 360

Simplifying the equation, we get:

x + y = 360

Now we have a system of equations:

x + y = 360 (Equation 1)

We also know that the brother used all his money to buy the notebooks, so x = 0.

Substituting x = 0 into Equation 1, we get:

0 + y = 360

Simplifying, we find that y = 360.

Therefore, the sister had 360 rubles and the brother had 0 rubles.

Answer

The sister had 360 rubles and the brother had 0 rubles.