Question

На субботник пришли 42 ученика и убрали школьный двор за 5,5 часов. сколько учеников должно прийти на субботник, что бы убрать весь школьный двор за 3 часа? производительность труда всех учеников одинакова. ответ:____уч. быстрей если можно, пожалуйста

Answer 1

Ответ:

Пошаговое объяснение:

42 ученика - 5,5 часа

х учеников - 3 часа

х/42= 5,5 /3

3х= 42 * 5,5

3х= 231

х= 231 : 3

х= 77 учеников должно прийти на субботник

Answer 2

Problem Analysis

We are given that 42 students cleaned the schoolyard in 5.5 hours. We need to determine how many students should come to clean the entire schoolyard in 3 hours, assuming that the productivity of all students is the same.

Solution

To solve this problem, we can use the concept of productivity. Productivity is defined as the amount of work done per unit of time. If the productivity of all students is the same, we can set up a proportion to find the number of students needed.

Let's denote the number of students needed as x.

The proportion can be set up as follows:

42 students / 5.5 hours = x students / 3 hours

To solve for x, we can cross-multiply and then divide:

42 students * 3 hours = 5.5 hours * x students

126 students = 5.5x students

x = 126 students / 5.5

x ≈ 22.91 students

Since we cannot have a fraction of a student, we need to round up to the nearest whole number. Therefore, 23 students should come to clean the entire schoolyard in 3 hours.

Answer

To clean the entire schoolyard in 3 hours, approximately 23 students should come to the cleanup.

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