Question

Можно пожалуйста решение на эту задачу без х! В нашем классе 35 человек. За первую четверть пятёрки по русскому языку имели 14 человек,по математике-12, по истории- 23. По русскому и математике-4, по математике и истории- 9,по русскому и истории- 5. Сколько учеников имеют пятерки по всем трём предметам , если в классе нет ни одного ученика, не имеещего пятерки хотя бы по одному из этих предметов?

Answer 1

Ответ:
По математике-12
По русскому-14
По истории-23
Решение:
4+9+5=18(уч)
35:18=3(уч)-имеющие пять
Пошаговое объяснение:

Answer 2

Task Analysis

The problem involves determining the number of students who have received top grades in all three subjects, given the total number of students in the class and the number of students who received top grades in each subject, as well as the number of students who received top grades in combinations of two subjects.

Solution

To solve this problem, we can use the principle of inclusion-exclusion. We'll start by adding the number of students who received top grades in each subject, then subtract the number of students who received top grades in combinations of two subjects, and finally add back the number of students who received top grades in all three subjects.

Let's calculate it step by step.

Step 1: Calculate the Total Number of Students with Top Grades in Each Subject

- Russian Language (R): 14 students - Mathematics (M): 12 students - History (H): 23 students

Step 2: Calculate the Number of Students with Top Grades in Combinations of Two Subjects

- R and M: 4 students - M and H: 9 students - R and H: 5 students

Step 3: Calculate the Total Number of Students with Top Grades in All Three Subjects

We can use the principle of inclusion-exclusion to find the number of students who have top grades in all three subjects.

Step 4: Apply the Principle of Inclusion-Exclusion

The formula for the principle of inclusion-exclusion is: Total = R + M + H - (R and M) - (M and H) - (R and H) + (R and M and H)

Let's calculate the total number of students who have top grades in all three subjects.

Calculation

- Total = 14 (R) + 12 (M) + 23 (H) - 4 (R and M) - 9 (M and H) - 5 (R and H) + (R and M and H)

Result

The total number of students who have top grades in all three subjects is the result of the calculation.

I hope this helps! If you have any further questions, feel free to ask.