There are 35 floors, 15 black tiles and 20 white tiles. If the floor area is 28 square meters, what are the areas of white tiles and black tiles

There are 35 floors, 15 black tiles and 20 white tiles. If the floor area is 28 square meters, what are the areas of white tiles and black tiles

Black tile = 28 / 35 * 15 = 12 M2
White tile = 28 / 35 * 20 = 16 M2

For a floor, there are 15 black tiles and 20 white tiles. The length of each side is equal to 0.7 cm. Please write down the area ratio of the two tiles and simplify them

Let the area be x, s black = 15 * x ^ 2, s White = 20 * x ^ 2, then x ^ 2 can be reduced, s Black: s White = 3:4

Write the floor area ratio of two kinds of floor tiles, and simplify (black brick 20, white brick 40)

20²：40²=400：1600=1：4

A piece of iron wire can be enclosed into a square with a side length of 9.42 cm. If it is enclosed into a circle, how many square centimeters is the area of the circle?

The perimeter of a square with a side length of 9.42 cm is equal to that of a circle
Radius of circle = 9.42 × 4 △ 3.14 △ 2 = 6cm
Area = 6 × 6 × 3.14 = 113.04 square centimeter

A square surrounded by iron wire is 15.7 cm long. Now it is surrounded by a circle. What is the area of the circle

15.7 × 4 = 62.8 (CM)
62.8 ﹣ 3.14 ﹣ 2 = 1 (CM) radius
3.14 × 1 & # 178; = 3.14 (square centimeter)

When a wire is used to form a square, its side length is 78.5cm. If it is used to form a circle, how many square centimeters is the area of the circle?

Radius 78.5x4 △ 2x3.14 = 50cm
Area 50x50x3.14 = 7850 square centimeter

It takes 2000 pieces to pave the floor with 15cm square bricks. If we use 25cm square bricks instead, how many pieces?

Suppose x square bricks are required. 25 × 25 × x = 15 × 15 × 2000 & nbsp; & nbsp; & nbsp; 625x = 225 × 2000 625x △ 625 = 225 × 2000 △ 625 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; X = 720; a: 720 square bricks are required

It takes 2000 pieces to use a 15 cm square brick to pave the floor of the classroom. If you use a 25 cm square brick to pave the floor, how many bricks do you need?
I will give a lot of points

We need x bricks
(15*15):(25*25)=x:2000
x=720
That's 720 yuan

It takes 3000 pieces to use 15 cm square bricks to pave the classroom floor. If you use 25 cm square bricks to pave the classroom floor, how many bricks do you need?

Area = 15 * 15 * 3000 = 675000; 25 * 25 * x = 675000, x = 1080 pieces if 25 cm is used

It takes 2000 pieces to pave the floor with 15cm square bricks. If we use 25cm square bricks instead, how many pieces?

Suppose x square bricks are required. 25 × 25 × x = 15 × 15 × 2000 & nbsp; & nbsp; & nbsp; 625x = 225 × 2000 625x △ 625 = 225 × 2000 △ 625 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; X = 720; a: 720 square bricks are required