Question

В пятом классе 7 школьников ходят в бассейн каждый день,9- через день, а остальные вообще не умеют плавать. Вчера в бассейн пришли 13 школьников.Сколько школьников придет в бассейн сегодня? А) 8 В) 9 С) 10 Д) невозможно решить

Answer 1

Если 7 человек каждый день пришёл,значит,13-7=6 приходил из тех детей,который через день приходят.9-6=3 человека придёт следующий день,то есть,сегодня и ещё 7 человек,который каждый день ходит,итого 3+7=10 человек.ответ:С

Answer 2

Problem Analysis

In the fifth grade, there are 7 students who go to the pool every day, 9 students who go every other day, and the rest of the students cannot swim at all. Yesterday, 13 students came to the pool. We need to determine how many students will come to the pool today.

Solution

To solve this problem, we need to consider the different groups of students who go to the pool.

1. Group 1: Students who go to the pool every day - There are 7 students in this group. - These students will come to the pool today.

2. Group 2: Students who go to the pool every other day - There are 9 students in this group. - Yesterday, 13 students came to the pool, which means that some students from this group came to the pool. - To determine how many students from this group came to the pool yesterday, we can subtract the number of students who go to the pool every day (7) from the total number of students who came to the pool yesterday (13). - So, 13 - 7 = 6 students from this group came to the pool yesterday. - Since these students go to the pool every other day, they will not come to the pool today.

3. Group 3: Students who cannot swim - The remaining students who did not fall into Group 1 or Group 2 cannot swim. - These students will not come to the pool today.

Therefore, the number of students who will come to the pool today is the sum of the students from Group 1 who go to the pool every day.

Answer

Based on the given information, the number of students who will come to the pool today is 7 (Option A).

Explanation

- Group 1 consists of 7 students who go to the pool every day. - Group 2 consists of 9 students who go to the pool every other day, but 6 of them came to the pool yesterday. - The remaining students cannot swim and will not come to the pool today.

Therefore, the correct answer is 7 (Option A).