In a cuboid glass jar with a length of 50 cm and a width of 40 cm, put a cube iron block with an edge length of 10 cm. At this time, the water depth is 20 cm A piece of iron is taken out of the cylinder. What is the depth of water in the cylinder?

5 cm
（50×40×20－10×10×10）÷（50×40）＝39000÷2000＝19.5

In a glass jar with a length of 25 cm and a width of 20 cm, there is a cube iron block with an edge length of 10 cm. At this time, the water depth is 15 cm. If the iron block is taken out of the jar, what is the water depth in the jar?

25 × 20 × 15-10 × 10 = 7500-1000 = 6500 (cubic centimeter) 6500 △ 25 × 20 = 6500 △ 500 = 13 (centimeter) answer: the water depth in the tank is 13 centimeter

In ancient times, how many were one foot, one foot and one inch
Guan Yu is 9 feet, Zhang Fei is 8 feet, and Liu Bei is 7 feet. What's the difference

The dimensions of each dynasty represent different lengths
summer
1 foot = 10 inches (1 foot = 24.9 cm)
merchant
1 foot = 10 inches, 1 inch = 10 minutes (1 foot = 31.1cm)
week
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 19.9 cm)
Qin Dynasty
1 lead = 10 Zhang, 1 Zhang = 10 feet, 1 foot = 10 inches, 1 inch = 10 minutes (1 foot = 27.7 cm)
Chinese
1 lead = 10 Zhang, 1 Zhang = 10 feet, 1 foot = 10 inches, 1 inch = 10 minutes (1 foot = 27.7 cm)
Xin Mang
1 lead = 10 Zhang, 1 Zhang = 10 feet, 1 foot = 10 inches, 1 inch = 10 minutes (1 foot = 23 cm)
three countries
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 24.1cm)
The Western Jin Dynasty
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 23 cm)
Eastern Jin Dynasty
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 24.5cm)
the Sixteen Kingdoms
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 24.5cm)
The southern and Northern Dynasties
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 24.5 cm; one foot = 29.6 cm)
Sui Dynasty
1 foot = 10 feet, 1 foot = 10 inches, 1 inch = 10 minutes (early stage: 1 foot = 29.6cm; later stage: 1 foot = 23.5cm)
Tang Dynasty;
Five Dynasties
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (small foot: one foot = 31.1 cm; large foot: one foot = 36 cm)
Song Dynasty
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 30.7 cm)
element
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 30.7 cm)
bright
1 foot = 10 feet, 1 foot = 10 inches, 1 inch = 10 minutes (tailoring ruler: 1 foot = 34 cm; floor measuring ruler: 1 foot = 32.7 cm; construction ruler: 1 foot = 31.1 cm)
clear
1 foot = 10 feet, 1 foot = 10 inches, 1 inch = 10 minutes (tailoring ruler: 1 foot = 35.5 cm; floor measuring ruler: 1 foot = 34.5 cm; construction ruler: 1 foot = 32 cm)
modern
One foot = 10 feet, one foot = 10 inches, one inch = 10 minutes (one foot = 33.33 cm)
The current length: Guan Yu 216.90cm, Zhang Fei 192.80cm, Liu Bei 168.70cm

The scale of the plan of a teaching building is 1:200, the distance on the map is 1.2 cm, and the actual length is () cm
The scale of the plan of a teaching building is 1:200, the distance on the map is 1.2 cm, and the actual length is () cm, or () M

Actual length 15000 and 150

The sum of the internal angles of a triangle is equal to 180 degrees. It is known that the first internal angle of a triangle is equal to three times of the second internal angle, and the third internal angle is 15 degrees larger than the second internal angle. What is the degree of each angle?

Let the second internal angle be x, the first internal angle be 3x, the third internal angle be x + 15 °, the sum of internal angles of ∵ triangle be 180 °, and the solution be x = 33 °, the first internal angle be 3x = 99 °, the second internal angle be 33 ° and the third internal angle be 48 °

Square of (x + 1) = square of (1-2x)

Square of (x + 1) - (1-2x) = 0
(x+1+1-2x)(x+1-1+2x)=0
3x(2-x)=0
∴x=0 x=2

A rectangular piece of land, 125 meters long and 50 meters wide, is now planted in its four corners and around, so that the distance between each adjacent two trees is equal
At least how many trees should be planted? Answer accurately, explain clearly, and don't miss a step

You should plant at least 14. You can take the greatest common multiple of 125 and 50, that is 25. Then divide the perimeter of the rectangle by 25. The result is 14

What do you learn in the first grade geography class in American primary schools?

Classroom teaching: the layers of the earth self wrote the article "what do you learn in the first grade of American primary school?" some netizens pointed out that the book "what should your n-grade children know" in the United States is not a textbook, and some netizens pointed out that not all American primary schools can speak so much

How to calculate 5 / 3 X-1 - x > 1

Multiply all by three first
5x-1-3x＞3
x＞2

How to draw a classroom plan?

It's a top view from the top. It's made up of rectangles

In a cuboid glass jar with a length of 50 cm and a width of 40 cm, put a cube iron block with an edge length of 10 cm. At this time, the water depth is 20 cm A piece of iron is taken out of the cylinder. What is the depth of water in the cylinder?