Question

На пограничном контроле в стране N рано утром работали всего три пограничника. Первому пограничнику нужно 4 минут, чтобы проверить паспорт, второму – 5 минут, третьему – 7 минут. Последним рейсом прилетело 75 человек, которые хотят пройти пограничный контроль как можно быстрее. За какое наименьшее время они смогут это сделать? Будем считать, что как только один человек прошел пограничный контроль, на его место тут же встает следующий из очереди (то есть, на перемещение людей время не тратится).

Answer 1

За 400 минут(6ч. 40мин.)

Answer 2

Problem Analysis

In this problem, we are given that there are three border guards working at a border control in country N early in the morning. Each guard takes a different amount of time to check a passport: the first guard takes 4 minutes, the second guard takes 5 minutes, and the third guard takes 7 minutes. The last flight arrived with 75 people who want to go through border control as quickly as possible. We need to determine the minimum amount of time it will take for all 75 people to go through border control, assuming that as soon as one person finishes, the next person immediately takes their place in line.

Solution

To find the minimum amount of time it will take for all 75 people to go through border control, we need to calculate the time it takes for each guard to process all the people.

Let's calculate the time for each guard:

- The first guard takes 4 minutes to check a passport. - The second guard takes 5 minutes to check a passport. - The third guard takes 7 minutes to check a passport.

Since each person goes to the next available guard as soon as the previous person finishes, we can calculate the total time it will take for all 75 people to go through border control by summing up the time it takes for each guard to process all the people.

The total time for the first guard to process all 75 people is calculated as follows: 75 people * 4 minutes/person = 300 minutes.

The total time for the second guard to process all 75 people is calculated as follows: 75 people * 5 minutes/person = 375 minutes.

The total time for the third guard to process all 75 people is calculated as follows: 75 people * 7 minutes/person = 525 minutes.

To find the minimum amount of time it will take for all 75 people to go through border control, we need to find the maximum time among the three guards. In this case, the third guard takes the longest time, which is 525 minutes.

Therefore, the minimum amount of time it will take for all 75 people to go through border control is 525 minutes.

Answer

The 75 people will be able to go through border control in a minimum of 525 minutes.