Question

В магазине «Канцтовары» в первой половине дня 30 человек покупали школьные тетради. 19 человек покупали только тетради «в клеточку», 18 человек покупали тетради только «в линейку». Были ли среди 30 покупателей те, которые покупали тетради двух видов (в клетку и линейку)? Если да, то, сколько таких покупателей было?

Answer 1

18+19=37. 37-30=7. Ответ 7

Answer 2

Analysis and Solution

To determine if there were any customers who purchased both "в клеточку" and "в линейку" notebooks, we can use the information provided about the number of customers who purchased each type of notebook separately.

According to the information given: - 19 customers purchased only "в клеточку" notebooks. - 18 customers purchased only "в линейку" notebooks. - The total number of customers who made purchases was 30.

To find the number of customers who purchased both types of notebooks, we can subtract the sum of customers who purchased only one type of notebook from the total number of customers.

Let's calculate it:

Total number of customers who purchased only "в клеточку" notebooks: 19 Total number of customers who purchased only "в линейку" notebooks: 18 Total number of customers who made purchases: 30

Number of customers who purchased both types of notebooks: (Total number of customers) - (Total number of customers who purchased only "в клеточку" notebooks) - (Total number of customers who purchased only "в линейку" notebooks)

Number of customers who purchased both types of notebooks: 30 - 19 - 18 = 13

Therefore, there were 13 customers who purchased both "в клеточку" and "в линейку" notebooks.

Please let me know if there is anything else I can help you with!