Question

Помогите решить в python 1. На уроке лит-ры учитель решил узнать, кто из 40 учеников читал книги А, В и С. Результаты опросы выглядят так: А - 25 уч., В - 22 уч., С - 22 уч.; одну из книг А или В - 33 уч., А или С - 32 уч., В или С - 31 уч, все три книги прочитали 10 учеников. Сколько учеников прочитали по одной книге? Сколько учеников прочитали ровно 2 книги? Сколько учеников не прочитали ни одной книги?

Answer 1

Ответ:

Попробуйте так:

1) 25 + 22 - 33 = 14 (учеников) - читали книги Пушкина и Лермонтова,

2) 25 + 22 - 31 = 16 (учеников) - читали книги Пушкина и Гоголя,

3) 22 + 22 - 32 = 12 (учеников) - читали книги Гоголя и Лермонтова,

4) 25 + 22 + 22 - 14 - 16 - 12+10 = 37 (учеников) - читали книги хотя бы одного из этих писателей ,

5) 40 - 37 = 3 (ученика) - не знакомы с произведениями этих писателей,

6) 25 - 16 - 14 + 10 = 5 (учеников) - читали книги только Пушкина,

7) 22 - 16 - 12 + 10 = 4 (ученика) - читали книги только Гоголя,

8) 22 - 14 - 12 + 10 = 6 (учеников) - читали книги только Лермонтова,

9) 5 + 4 + 6 = 15 (учеников) - прочли книги только одного из этих авторов.

Ответ. 3 ученика не знакомы с произведениями этих писателей; 15 учеников прочли книги только одного автора.

Answer 2

Problem Analysis

We are given the following information: - There are 40 students in the literature class. - The results of the survey are as follows: - 25 students read book A. - 22 students read book B. - 22 students read book C. - 33 students read either book A or book B. - 32 students read either book A or book C. - 31 students read either book B or book C. - 10 students read all three books.

We need to determine the following: 1. How many students read exactly one book? 2. How many students read exactly two books? 3. How many students did not read any book?

Solution

To solve this problem, we can use the principle of inclusion-exclusion. Let's break down the solution step by step:

1. How many students read exactly one book? - We know that 25 students read book A, 22 students read book B, and 22 students read book C. - To find the number of students who read exactly one book, we need to subtract the number of students who read two or three books from the total number of students who read each book. - Let's calculate the number of students who read two or three books: - The number of students who read either book A or book B is 33. - The number of students who read either book A or book C is 32. - The number of students who read either book B or book C is 31. - The number of students who read all three books is 10. - Now, let's calculate the number of students who read exactly one book: - For book A: 25 - (33 - 10) = 2. - For book B: 22 - (33 - 10) = -1 (since we can't have negative students). - For book C: 22 - (32 - 10) = 0. - Therefore, 2 students read exactly one book.

2. How many students read exactly two books? - We have already calculated the number of students who read exactly one book, which is 2. - To find the number of students who read exactly two books, we need to subtract the number of students who read only one book from the total number of students who read two or three books. - Let's calculate the number of students who read two or three books: - The number of students who read either book A or book B is 33. - The number of students who read either book A or book C is 32. - The number of students who read either book B or book C is 31. - The number of students who read all three books is 10. - Now, let's calculate the number of students who read exactly two books: - For book A and B: 33 - 10 - 2 = 21. - For book A and C: 32 - 10 - 0 = 22. - For book B and C: 31 - 10 - 0 = 21. - Therefore, the number of students who read exactly two books is 21 + 22 + 21 = 64 students.

3. How many students did not read any book? - To find the number of students who did not read any book, we need to subtract the number of students who read at least one book from the total number of students. - The total number of students is 40. - The number of students who read at least one book is the sum of the number of students who read each book minus the number of students who read all three books: - Students who read book A: 25 - 10 = 15. - Students who read book B: 22 - 10 = 12. - Students who read book C: 22 - 10 = 12. - Now, let's calculate the number of students who did not read any book: - 40 - (15 + 12 + 12) = 1. - Therefore, 1 student did not read any book.

Summary

Based on the given information, we can conclude the following: - 2 students read exactly one book. - 64 students read exactly two books. - 1 student did not read any book.