Question

Первая бригада может посадить 600 деревьев за 10 дней , вторая за 12 дней , а третья за 15 дней . За сколько дней 3 бригады смогут посадить эти деревья работая вместе ?

Answer 1

600:10=60(дер/день) 1 бригада
600:12=50(дер/день) 2 бригада
600:15=40(дер/день) 3 бригада
60+50+40=150(дер/день) вместе
600:150=4(дня)

Answer 2

Problem Analysis

We are given three brigades that can plant a certain number of trees in a given number of days. We need to determine how many days it will take for all three brigades to plant the trees together.

Solution

To solve this problem, we can calculate the rate at which each brigade plants trees and then combine their rates to find the total rate at which they can plant trees together. Finally, we can use this combined rate to calculate the number of days required to plant all the trees.

Let's calculate the rate at which each brigade plants trees: - The first brigade can plant 600 trees in 10 days. Therefore, their rate is 600 trees / 10 days = 60 trees per day. - The second brigade can plant 600 trees in 12 days. Therefore, their rate is 600 trees / 12 days = 50 trees per day. - The third brigade can plant 600 trees in 15 days. Therefore, their rate is 600 trees / 15 days = 40 trees per day.

Now, let's calculate the combined rate of all three brigades: - Combined rate = rate of first brigade + rate of second brigade + rate of third brigade - Combined rate = 60 trees per day + 50 trees per day + 40 trees per day = 150 trees per day.

Finally, let's calculate the number of days required to plant all the trees: - Number of days = total number of trees / combined rate - Number of days = 600 trees / 150 trees per day = 4 days.

Therefore, it will take all three brigades working together 4 days to plant all the trees.

Answer

It will take the three brigades working together 4 days to plant all the trees.