Question

Помогите решить задачу!!!!!Одна бригада рабочих может заасфальтировать 15 км шоссейной дороги за 30 дней, а другая-за 60 дней.За сколько дней могут заасфальтировать эту дорогу обе бригады,работая вместе?

Answer 1

15000 : 30 = 500 м в день - производительность первой бригады
15000 : 60 = 250 м в день - производительность второй бригады
15000 : (500 + 250) = 20 дней
Ответ: за 20 дней

Answer 2

Problem Analysis

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

Solution

Let's assume that the combined rate of work for both teams is x km/day.

According to the problem, the first team can pave 15 km in 30 days, which means their rate of work is 15 km / 30 days = 0.5 km/day. Similarly, the second team can pave 15 km in 60 days, so their rate of work is 15 km / 60 days = 0.25 km/day.

To find the combined rate of work, we can add the rates of work for both teams:

Combined rate of work = Rate of work for Team 1 + Rate of work for Team 2

x km/day = 0.5 km/day + 0.25 km/day

Simplifying the equation, we get:

x km/day = 0.75 km/day

Now, we can determine the number of days it will take for both teams to pave the entire highway by dividing the total distance (15 km) by the combined rate of work (0.75 km/day):

Number of days = Total distance / Combined rate of work

Number of days = 15 km / 0.75 km/day

Simplifying the equation, we get:

Number of days = 20 days

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

Answer

Both teams working together can pave the entire highway in 20 days.