Question

Помогите пожалуйста!!!Первая бригада может отремонтировать 1800 м дороги за 90 дней, а вторая - за 45 дней. За сколько дней будет закончен ремонт этой дороги, если обе бригады будут работать совместно?

Answer 1

1800 : 90 = 20 ( человек )- нужно чтобы отремонтировать 1800 м дороги за 90 дней
1800 : 45 = 40 ( человек ) чтобы отремонтировать 1800 м за 45 днй
40 + 20 = 60 ( человек ) - будут работать вмесе
1800 : 60 = 30 ( дней )
Ответ : за 30 дней

Answer 2

1. 1800 : 90 = 20 (м) ремонтирует 1 бригада в день2. 1800 : 45 = 40 (м) ремонтирует 2 бригада в день3. 20 + 40 = 60 (м) будут ремонтировать обе бригады в день работая вместе4. 1800 : 60 = 30 дней понядобится бригадам при совместной работе.Ответ. 30 дней.

Answer 3

Problem Analysis

We are given that the first team can repair 1800 meters of road in 90 days, and the second team can repair the same length of road in 45 days. We need to determine how many days it will take for both teams to complete the repair work if they work together.

Solution

To solve this problem, we can use the concept of work rates. The work rate of a team is the amount of work they can complete in a given time. We can calculate the work rate of each team using the formula:

Work Rate = Amount of Work / Time

Let's calculate the work rates for both teams:

- First team's work rate: 1800 meters / 90 days = 20 meters/day - Second team's work rate: 1800 meters / 45 days = 40 meters/day

Now, when both teams work together, their work rates will add up. So the combined work rate of both teams is:

Combined Work Rate = First Team's Work Rate + Second Team's Work Rate

Substituting the values, we get:

Combined Work Rate = 20 meters/day + 40 meters/day = 60 meters/day

Now, we can use the combined work rate to calculate the number of days required to complete the repair work. Let's denote the number of days required as 'x'. We can use the formula:

Amount of Work = Work Rate * Time

Substituting the values, we get:

1800 meters = 60 meters/day * x days

Simplifying the equation, we find:

x = 1800 meters / 60 meters/day = 30 days

Therefore, it will take both teams 30 days to complete the repair work if they work together.

Answer

If both the first and second teams work together, it will take them 30 days to complete the repair of the road.