Question

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

15÷30=0,5 км в день- делает первая бригада
15÷60=0,25 км в день- делает вторая бригада в день
0,25+0,5=0,75 км в день- будут делать обе бригады, работая вместе
15÷0,75=20 дней
Ответ: за 20 дней обе бригады заасфальтируют дорогу, работая вместе.

Answer 2

Calculation of Days Required to Asphalt the Road

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

Let's assume that the first brigade can asphalt 15 km of the road in 30 days, and the second brigade can asphalt the same length of road in 60 days.

The work rate of the first brigade can be calculated as 15 km / 30 days = 0.5 km/day. The work rate of the second brigade can be calculated as 15 km / 60 days = 0.25 km/day.

To find the combined work rate of both brigades, we add their individual work rates:

0.5 km/day + 0.25 km/day = 0.75 km/day.

Therefore, the combined work rate of both brigades is 0.75 km/day.

To determine the number of days required for both brigades to asphalt the road together, we divide the total length of the road (15 km) by the combined work rate (0.75 km/day):

15 km / 0.75 km/day = 20 days.

Therefore, both brigades working together can asphalt the road in 20 days.

Answer

Both brigades, working together, can asphalt the road in 20 days.

Please note that the calculations provided are based on the given information and assumptions.