Question

Вадим купил для себя 18 тетрадей а для соседа 12 тетрадей по одинаковой цене.За всю покупку он заплатил 84 руб.Сосед принес ему купюру в 50 руб.Сколько сдачи Вадим должен ему вернуть?

Answer 1

18+12=30(тетр.)
84:30=2,8(за 1 шт.)
12*2.8=33.6(за тетр.соседа)
50-33.6=16.4(сдача)

Answer 2

Problem Analysis

To solve this problem, we need to find the amount of change that Vadim should give to his neighbor. We know that Vadim bought 18 notebooks for himself and 12 notebooks for his neighbor, and the total cost of the purchase was 84 rubles. The neighbor gave Vadim a 50 ruble bill. We need to calculate the amount of change Vadim should give to his neighbor.

Solution

To find the amount of change Vadim should give to his neighbor, we need to subtract the total cost of the notebooks from the 50 ruble bill.

Let's calculate the total cost of the notebooks first. We know that Vadim bought 18 notebooks for himself and 12 notebooks for his neighbor, and the total cost of the purchase was 84 rubles. We can set up the following equation:

18x + 12x = 84

Where x represents the cost of each notebook.

Simplifying the equation, we get:

30x = 84

Now, let's solve for x:

x = 84 / 30 x = 2.8

Therefore, each notebook costs 2.8 rubles.

Now, let's calculate the total cost of the notebooks for Vadim's neighbor:

12 * 2.8 = 33.6 rubles

Now, let's calculate the amount of change Vadim should give to his neighbor:

50 - 33.6 = 16.4 rubles

Therefore, Vadim should give his neighbor 16.4 rubles in change.

Answer

Vadim should give his neighbor 16.4 rubles in change.