With a rope around the column circle, the rope is more than 40 cm, if around the column three circles, the rope is less than 20 cm, how long is the rope! With a rope around the post 2 times, the rope is more than 40 cm, if around the post 3 times, the rope is less than 20 cm, how long is the rope!

With a rope around the column circle, the rope is more than 40 cm, if around the column three circles, the rope is less than 20 cm, how long is the rope! With a rope around the post 2 times, the rope is more than 40 cm, if around the post 3 times, the rope is less than 20 cm, how long is the rope!

Let X be the length of the rope and y the circumference of the column
X=Y+40
X=3Y-20
The calculation results show that: x = 70cm, y = 30cm
So the length of the rope should be 70 cm

If you use a rope to wrap around the column for 2 turns, the rope will be 40 cm more. If you wrap around the column for 3 turns, the rope will be 10 cm less. What is the perimeter of the column? How long is the rope?

The perimeter of the column is x? The length of the rope is y
2X=Y-40
3X=Y+10
X=50,Y=140
The perimeter of the column is 50 cm and the length of the rope is 140 cm

There are four square pillars in the school auditorium. Each square pillar is 3.5 meters high and its cross section is a square with a side length of 6 decimeters. Now we need to paint these four pillars. If every square meter is filled with oil

I'm not finished with your question. But to finish all the painting, so many columns need painting
0.6 * 4 * 3.5 * 4 = 33.6 square meters
If you ask for X yuan per square meter of paint, you only need to multiply 33.6 times x to get your price