Question

Задание 2 (50 баллов). В летний лагерь приехали три подруги: Маша, Катя и Полина. Известно, что каждая девочка имеет одну из следующих фамилий: Петрова, Семёнова и Сидорова. Маша не Сидорова. Мама Кати – врач. Катя учится в 5 классе. Сидорова учится в 4 классе. Мама Петровой – повар. Какая фамилия у Полины? Решите задачу с помощью таблицы. Покажите полное решение. Под таблицей запишите ход решения.

Answer 1

Ответ: у Полины фамилия Сидорова
Объяснение: Сразу Маша не Сидорова, мама Кати врач и она учится в 5 классе, а Полина учится в 4 классе и поэтому Сидорова

Answer 2

Объяснение:

фамилия у Полины- Сидорова

Answer 3

Problem Analysis

To solve this problem, we need to determine the last name of Polina based on the given information. We know that there are three friends: Masha, Katya, and Polina. Each girl has one of the following last names: Petrova, Semyonova, or Sidorova. We also have the following additional information: - Masha is not Sidorova. - Katya's mother is a doctor. - Katya is in the 5th grade. - Sidorova is in the 4th grade. - Petrova's mother is a cook.

We will create a table to organize the information and use it to deduce the last name of Polina.

Solution

| Friend | Last Name | Mother's Profession | Grade | |--------|-----------|---------------------|-------| | Masha | | | | | Katya | | | | | Polina | | | |

From the given information, we can fill in the table as follows:

| Friend | Last Name | Mother's Profession | Grade | |--------|-----------|---------------------|-------| | Masha | | | | | Katya | | Doctor | 5 | | Polina | | | |

We know that Masha is not Sidorova, so she must be either Petrova or Semyonova. Since we don't have any information about Masha's mother's profession or grade, we cannot determine her last name at this point.

| Friend | Last Name | Mother's Profession | Grade | |--------|-----------|---------------------|-------| | Masha | Petrova? | | | | Katya | | Doctor | 5 | | Polina | | | |

We know that Katya's mother is a doctor, so Katya cannot be Sidorova. Therefore, Katya must be either Petrova or Semyonova. Since we don't have any information about Katya's grade, we cannot determine her last name at this point.

| Friend | Last Name | Mother's Profession | Grade | |--------|-----------|---------------------|-------| | Masha | Petrova? | | | | Katya | Petrova? | Doctor | 5 | | Polina | | | |

We know that Sidorova is in the 4th grade, so Masha cannot be Sidorova. Therefore, Masha must be Semyonova.

| Friend | Last Name | Mother's Profession | Grade | |--------|-----------|---------------------|-------| | Masha | Semyonova | | | | Katya | Petrova? | Doctor | 5 | | Polina | | | |

Since Masha is Semyonova, Katya cannot be Petrova because each girl must have a different last name. Therefore, Katya must be Sidorova.

| Friend | Last Name | Mother's Profession | Grade | |--------|-----------|---------------------|-------| | Masha | Semyonova | | | | Katya | Sidorova | Doctor | 5 | | Polina | | | |

Now we only have one last name left, which is Petrova. Therefore, Polina's last name must be Petrova.

| Friend | Last Name | Mother's Profession | Grade | |--------|-----------|---------------------|-------| | Masha | Semyonova | | | | Katya | Sidorova | Doctor | 5 | | Polina | Petrova | | |

Conclusion

Based on the given information, the last name of Polina is Petrova.

Note: The solution provided above is based on the given information and logical deductions.