Question

Помогите решить задачу одна бригада рабочих может заасфальтировать 15 километров шоссейной дороге за 30 дней а другая за 60 дней за сколько дней могут заасфальтировать эту дорогу обе бригады работая вместе

Answer 1

15км=15000м
1)15000:30=500м/д- 1 бр.
2)15000:60=250м/д-2бр.
3)500+250=750м/д- о
бе бригады вместе
4)15000:750=20дней

Answer 2

Problem Analysis

We are given that one team of workers can pave a 15-kilometer highway in 30 days, while another team can pave the same highway in 60 days. We need to determine how many days it will take for both teams to pave the highway if they work together.

Solution

Let's assume that the combined rate of work for both teams is x kilometers per day. We can set up the following equation based on the given information:

Team 1's rate of work: 15 kilometers / 30 days = 0.5 kilometers per day. Team 2's rate of work: 15 kilometers / 60 days = 0.25 kilometers per day.

When both teams work together, their combined rate of work is x kilometers per day.

According to the principle of work, the sum of individual rates of work is equal to the combined rate of work. Therefore, we can write the equation:

0.5 kilometers per day + 0.25 kilometers per day = x kilometers per day.

Simplifying the equation, we get:

0.75 kilometers per day = x kilometers per day.

This means that when both teams work together, they can pave 0.75 kilometers per day.

To find the number of days it will take for both teams to pave the entire 15-kilometer highway, we can set up the following equation:

0.75 kilometers per day * number of days = 15 kilometers.

Simplifying the equation, we get:

number of days = 15 kilometers / 0.75 kilometers per day.

Calculating the result, we find:

number of days = 20 days.

Therefore, it will take both teams working together 20 days to pave the entire 15-kilometer highway.

Answer

Both teams working together can pave the 15-kilometer highway in 20 days.