Question

В группе из 50 ребят некоторые знают все буквы, кроме <<р>>, которую просто пропускают при письме, а остальные ребята знают все буквы, кроме <<к>>, которую так же пропускают. Однажды учитель попросил 15 учеников написать слово <<кот>>, 25 других учеников — написать слово <<рот>>, а остальных учеников — слово <<крот>>. При этом слова <<кот>> и <<рот>> оказались написанными по 20 раз. Сколько ребят написали своё слово верно?

Answer 1

30 школьников смогли написать прпаильно

Answer 2

Problem Analysis

The problem describes a group of 50 students, some of whom do not know the letter "р" and others who do not know the letter "к". The teacher asked 15 students to write the word "кот", 25 students to write the word "рот", and the remaining students to write the word "крот". The words "кот" and "рот" were each written 20 times.

Solution

To solve this problem, we can use a systematic approach to determine the number of students who wrote their word correctly.

Let's start by analyzing the information provided and then proceed with the solution.

Analysis

1. There are 50 students in the group. 2. Some students do not know the letter "р", and others do not know the letter "к". 3. 15 students were asked to write the word "кот". 4. 25 students were asked to write the word "рот". 5. The remaining students were asked to write the word "крот". 6. The words "кот" and "рот" were each written 20 times.

Solution Steps

1. Determine the number of students who know both "к" and "р". 2. Calculate the number of students who wrote their word correctly.

Step 1: Determine the Number of Students Who Know Both "к" and "р"

Let's calculate the number of students who know both "к" and "р".

The number of students who know "к" = Total students - (students who don't know "к") The number of students who know "р" = Total students - (students who don't know "р")

Step 2: Calculate the Number of Students Who Wrote Their Word Correctly

Now, we can calculate the number of students who wrote their word correctly based on the information provided.

The number of students who wrote "кот" correctly = (Students who know both "к" and "р") - (Students who wrote "рот") The number of students who wrote "рот" correctly = (Students who know both "к" and "р") - (Students who wrote "кот") The number of students who wrote "крот" correctly = Total students - (Students who wrote "кот" or "рот")

Let's proceed with the calculations based on the given information.

Calculation

The number of students who know "к" = 50 - 20 = 30 The number of students who know "р" = 50 - 20 = 30

The number of students who wrote "кот" correctly = 30 - 25 = 5 The number of students who wrote "рот" correctly = 30 - 15 = 15 The number of students who wrote "крот" correctly = 50 - (20 + 20) = 10

Conclusion

Therefore, 5 students wrote the word "кот" correctly, 15 students wrote the word "рот" correctly, and 10 students wrote the word "крот" correctly.

If you have any further questions or need additional assistance, feel free to ask!