Students went to plant trees. The first group planted 18 trees in 30 minutes, and the second group planted 12 trees in 18 minutes. Which group planted trees faster?

Students went to plant trees. The first group planted 18 trees in 30 minutes, and the second group planted 12 trees in 18 minutes. Which group planted trees faster?

Group 1: 18 trees / 30 minutes = 3 / 5 trees / minute
The second group: 12 (trees) / 18 (minutes) = 2 / 3 (trees / minutes)
The first group: 3 / 5 = 9 / 15
Group 2: 2 / 3 = 10 / 15
By comparison, the second group is faster

There are 356 trees planted on one side of one kilometer. Every two trees are 10 meters apart. How long is the highway?

(356-1) * 10 = 3550m
Because every two trees are 10 meters apart, there are 355 sections
Let's take a simple example: if you draw 4 trees, do you have 3 spaces, 5 trees have 4 spaces, and so on, so 356 trees have 355 spaces. Think about it carefully!

Three tree planting teams planted 1900 trees. Team a planted twice as many trees as team B. Team B planted 300 fewer trees than team C. how many trees did each of the three teams plant?

Team B planted x, then a is 2x, and C is x + 300
2x+x+x+300=1900
4x=1600
x=400
A: a 800 B 400 C 700