1) The difference between the numbers A and B is 40, and the number A is three times that of the number B. Find the numbers A and B. ..

2) Students plant trees. The fifth grade is three times that of the fourth grade. It is known that the fifth grade has 42 more trees than the fourth grade. How many trees are there in two grades?

3) Xiaohua goes to the stationery store to buy pens and notebooks. Notebooks are more expensive than pens, 4.8 yuan. Knowing that notebooks cost three times as much as pens, how much is it?

Second, planting trees:

1) For example: (1) If you plant trees along a 60-meter-long road and plant them every 2 meters 1 tree, how many trees would you plant?

2) How many trees do tree planters plant on both sides and ends of a road at intervals of three meters?

2) For example, a section of 1 is 720 meters long, and there are no trees at one end of the road. How many trees can be planted every 3 meters in the future?

Planting trees on closed routes;

1 Trees were planted around the circular flower bed. It is known that the circumference is 945 meters and 270 trees have been planted. What is the distance between two adjacent trees?

The rectangular campus is 60 meters long and 28 meters wide. Plan to plant a tree every four meters around and how many trees to plant. (