Question

Мальчик купил 7 одинаковых карандашей, а девочка купила 11 таких же карандашей и за платила на 12 р. больше. Сколько стоит один карандаш? Сколько заплатила за свою покупку девочка и сколько заплатил мальчик? ​

Answer 1

1)11-7=4 - на 4 карандаша девочка купила больше чем мальчик
2)12:4=3 рублей стоит один карандаш
3)11*3=33 рублей заплатила девочка
4)7*3=21 рублей заплатил мальчик

Answer 2

Calculation of the Cost of One Pencil

To find the cost of one pencil, we can set up an equation based on the given information. Let's assume the cost of one pencil is represented by the variable 'x'.

The boy bought 7 identical pencils, so the cost of his purchase would be 7x.

The girl bought 11 identical pencils and paid 12 rubles more than the boy, so the cost of her purchase would be (7x + 12).

To find the value of 'x', we can set up the following equation:

7x + 12 = 11x

Simplifying the equation:

12 = 11x - 7x 12 = 4x

Dividing both sides by 4:

x = 3

Therefore, the cost of one pencil is 3 rubles.

Calculation of the Total Cost for Each Purchase

Now, let's calculate the total cost for each purchase.

The boy bought 7 pencils, and each pencil costs 3 rubles. So, the total cost of his purchase would be:

7 pencils * 3 rubles/pencil = 21 rubles

The girl bought 11 pencils, and each pencil costs 3 rubles. Additionally, she paid 12 rubles more than the boy. So, the total cost of her purchase would be:

11 pencils * 3 rubles/pencil + 12 rubles = 33 rubles + 12 rubles = 45 rubles

Therefore, the girl paid 45 rubles for her purchase, while the boy paid 21 rubles for his purchase.