Question

Строители первой бригады могут построить здание за 15 месяцев . Строители второй бригады - за две третих этого времени . За сколько месяцев могут построить задание две бригады , работая совместно ?

Answer 1

через пять минут дам решение

Answer 2

1) 15/3*2=10 мес - строители 2ой бригады могут построить здание
2) 1/15 - здания построит 1я бригада  за месяц
3) 1/10 - здания построит 2я бригада  за месяц
4) 1/15+1/10=1/6 - здания построят 2 бригады  за месяц
5) 1:1/6=6 мес - за столько месяцев могут построить задание две
     бригады , работая совместно

Answer 3

Calculating Construction Time for Two Brigades

To calculate the time it takes for two brigades to build a building working together, we can use the concept of "work done per unit time."

Let's denote: - Time taken by the first brigade to build the building as T1 (15 months) - Time taken by the second brigade to build the building as T2 (two-thirds of T1)

The combined rate of work for both brigades working together can be represented as: - 1/T1 + 1/T2 = 1/T

Where T is the time taken for both brigades working together to build the building.

Calculating the Combined Time

Given that the first brigade can build the building in 15 months and the second brigade can build it in two-thirds of this time, we can calculate the combined time as follows:

- T1 = 15 months - T2 = (2/3) * T1 = 10 months

Substitute these values into the equation: - 1/15 + 1/10 = 1/T

Solving for T: - 1/15 + 1/10 = 1/T - (2/30) + (3/30) = 1/T - 5/30 = 1/T - 1/6 = 1/T - T = 6 months

Therefore, the two brigades working together can build the building in 6 months.