Question

одна бригада рабочих может заасфальтировать 15км шоссейной дороги за 30 дней,а другая-за 60 дней.за сколько дней могут заасфальтировать эту дорогу обе бригады,работая вмести?

Answer 1

1)асфальтирует первая бригада за 1 день

15 км=15000м,значит

15000:30=500 м

2)асфальтирует вторая бригада за один день

15000:60=250 м

3)асфальтируют обе бригады за 1 день

500+250=750 м

4)за сколько дней заасфальтируют работая вместе?

15000:750=20 дней

Answer 2

Calculation of the Time Required to Asphalt the Road

To determine the number of days it would take for both brigades to asphalt the road together, we need to calculate their combined work rate.

Let's assume that Brigade A can asphalt 15 km of road in 30 days, and Brigade B can asphalt the same length of road in 60 days.

The work rate of Brigade A can be calculated as 1 km of road per 2 days (30 days divided by 15 km). Similarly, the work rate of Brigade B is 1 km of road per 4 days (60 days divided by 15 km).

To find the combined work rate of both brigades, we can add their individual work rates. The combined work rate is 1 km of road per (2 + 4) = 1 km of road per 6 days.

Therefore, both brigades working together can asphalt the entire road in 6 days.

Conclusion

Both brigades, working together, can asphalt the entire 15 km road in 6 days.