1 g of air, air density is 1.29 kg / M cubic, what is the volume of CM cubic?

The starting price of a taxi in a city is 6 yuan (within 3 kilometers), more than 3 kilometers, with an average of 1.2 yuan per kilometer. The three members of Congcong's family pay a total of 9.12 yuan by taxi from home to grandma's home. How far is Congcong's home from Grandma's home?

9.12-6 = 3.12 yuan
3.12/1.2=2.6km
2.6+3=5.6km

For a rectangle with a surface area of 217 cm2, the height is 7 cm, the width is 5 cm, and the height is 7 cm

1. Let the length be X
(7X+5X+7×5)×2=217
7X+5X+7×5=217÷2
12x=73.5
x=6.125
2. Volume = 6.125 × 5 × 7 = 214.375 (cm3)

Given the triangle ABC, the angle c = 120 degrees, C = 7, a + B = 8, find the value of COS (a-b)

a^2+b^2-2abcosC = c^2
a^2+b^2+ab = 49
And a + B = 8
a

The denominator is a natural number (including 100) within 100, which can be converted into a finite number. What are the fractional units? Write them out one by one

The denominator of a fraction that can be reduced to a finite number requires no other factors except 2 and 5
Therefore, within 100, any number with only 2 or 5 factors as denominator meets the requirements of the topic
1,2,4,5,8,10,16,20,25,32,40,50,64,80,100.

A piece of iron wire can form a square with a side length of 3.14 cm. If it is used to form a circle, the circumference of the circle is (), and the area is ()

Perimeter 3.14 * 4 = 12.56
2 * 3.14 * radius = 12.56 radius = 2
Area 3.14 * 2 * 2 = 12.56

When m is a positive integer, n is a positive odd number, and X is not equal to y, the m power of - (X-Y) multiplied by the n power of (Y-X) is equal to

-(x-y)^m*(y-x)^n=-(x-y)^m*[(-1)^n*(x-y)^n
==-(x-y)^m*[-(x-y)^n]=(x-y)^(m+n)

1. One cuboid warehouse, 50 meters long, 30 meters wide and 5 meters high, can hold up to 8 cubic meters of cube containers
2. There is a 20 cm long wire, which is used to form a quadrilateral with 4 cm on the opposite side. This quadrilateral may be (). 3. A project is completed by Party A and Party B in 20 days. It is known that the work efficiency ratio of Party A and Party B is 4:5, and it takes Party A () days to complete the project alone
4. The hour hand of a clock is 3cm long, and the distance its tip travels in a day and night is () cm
5. On a 10 decimeter long and 6 decimeter wide rectangular iron plate, at most () round iron plates with a diameter of 2 decimeters can be cut. 6 and 3 / 4 tons can be regarded as 3 tons (/) or 9 tons (/)
7. The ratio of edge length of two cubes is 1 ∶ 3. The surface area ratio of the two cubes is (): (), and the volume ratio is (): (). 8. The base angle of a triangle is 45 degrees, and its apex angle is (). This triangle is called () triangle
9. If these small cubes are arranged in a row in turn, they can be arranged into () meters. 10, 20% of a number is 100, and 3 / 5 of this number is ()
11. There are 48 attendants in class 6 (1) today, and 2 of them ask for leave because of illness. The attendance rate of this day is (). 12. If the quotient of a divided by B is 2, then a ∶ B = (): ()
13. 5 / 8 of a is equal to 5 / 12 of B, a: B = (): ()
14. Add 2.5 to the first term of 4 ∶ 15. In order to keep the ratio unchanged, add (). 15, 6 / 5 tons: 350 kg to the last term of the ratio. The simplified ratio is (), and the ratio is ()
16. After 1 / 8 of class A is transferred to class B, the number of people in the two classes is equal. The original number ratio of class A and class B is (). 17, the distance that class a takes is 4 / 5 of class B, the time that class B takes is 4 / 5 of class A, and the speed ratio of class A and class B is ()
18. A number is composed of five million, eight thousand, and 40 tens. This number is written (), which is rewritten into ten thousand, and the remainder after ten thousand is omitted
19. The number with only prime factor 2 within 50 is ()
20. The length of a rope is 4 meters. Divide it into 5 sections. Each section is () of the rope. The length is () meters. The unit of (). 21 and 3 / 8 of 1 meter is (). If you add () such units, it is 87.5%. 22. Fill in the brackets with a fraction whose denominator is one digit, 3 / 4 ＜ () < 4 / 5
The least common multiple of 23, 15 and 5 is () times of the greatest common divisor, and () times of their immediate greatest common divisor. This multiple is () of these two numbers
(1) For a project, team a will complete it in a day and team B will complete it in B day. If two teams cooperate, () days will be completed? (2) the quotient of the sum of a and 7 divided by 5 is () (3) the quotient of N divided by M is ()
25. A 2-meter-long wooden stick with a cross-sectional diameter of 6 cm increases its surface area by (), and its original volume is ()

1. One cuboid warehouse, 50 meters long, 30 meters wide and 5 meters high, can hold up to 750 cubic boxes of 8 cubic meters
2. There is a 20 cm long iron wire, which is used to form a quadrilateral with 4 cm on the opposite side. This quadrilateral may be (square). 3. For a project, team a and team B cooperate for 20 days. It is known that the work efficiency ratio of team a and team B is 4:5, and team a needs (4) days to complete the project alone
4. The length of the hour hand of a clock is 3cm, and the distance its tip travels in a day and night is (18.84cm)
5. On a 10 decimeter long and 6 decimeter wide rectangular iron plate, at most (15) round iron plates with a diameter of 2 decimeters can be intercepted. 6 and 3 / 4 tons can be regarded as 3 tons (1 / 4) or 9 tons (1 / 12)
7. The ratio of edge to length of two cubes is 1 ∶ 3, the ratio of surface area of the two cubes is (1) ∶ (9), and the ratio of volume is (1) ∶ (27). 8. The base angle of a triangle is 45 degrees, and its apex angle is (90). This triangle is called (right angle) triangle
9. At least (8) small cubes with 1 cm edge length need to be assembled into a larger cube, and (1000) large cubes with 1 decimeter edge length need to be assembled. If these small cubes are arranged in a row in turn, they can be arranged into (1000) meters. 10, 20% of a number is 100, and 3 / 5 of this number is (500)
11. There are 48 attendants in class 6 (1) today. Two of them ask for leave because of illness. The attendance rate is (98)%. 12. If the quotient of a divided by B is 2, then a ∶ B = (2) ∶ (1)
13. 5 / 8 of number a is equal to 5 / 12 of number B, number A: number b = (2) ∶ (3)
14. Add 2.5 to the first term of 4:15. In order to keep the ratio unchanged, add (9.375) to the second term of the ratio. 15, 6 / 5 tons: 350 kg. The simplified ratio is (130:7), and the ratio is (7 / 130)
16. After 1 / 8 of class A is transferred to class B, the number of people in the two classes is equal. The ratio of class A to class B is (4:3). 17. The distance that class a takes is 4 / 5 of that of class B, the time that class B takes is 4 / 5 of that of class A, and the speed ratio of class A to class B is (16:25)
18. A number is composed of 5 million, 8 thousand, 40 tens. The number writing (5008040) is rewritten into the number writing of (500804) million with the unit of ten thousand, and the mantissa writing after (5010000) is omitted
19. The numbers within 50 only contain prime factor 2 are (2,4,8,16,32)
20. A rope is 4 meters long, and it is divided into 5 sections. Each section is (1 / 5) of the rope, and (4 / 5) meters long, which is equal to (4 / 5) of 1 meter. The unit of 21 and 3 / 8 is (1 / 8), and it is 87.5% to add (4) such units
The least common multiple of 23, 15 and 5 is (3) times of the greatest common divisor, and () times of their immediate greatest common divisor. This multiple is () of these two numbers
(1) A project is completed by team a alone in a day and by team B alone in B day. Two teams cooperate, (AB / A + b) days to complete? (2) the quotient of 3 times of the sum of a and 7 divided by 5 is ((a + 7) × 3 △ 5). (3) the quotient of N divided by M is (m △ n)
25. A 2-meter-long wooden stick with a cross-sectional diameter of 6 cm increases its surface area by (169.56) after it is cut into 4 sections, and its original volume is (56.52)

If a cylinder is truncated by 6cm, its surface area will be reduced by 75.36cm2. How much is the volume of the cylinder reduced

What is the circumference of the base of the cylinder
75.36 △ 6 = 12.56 (CM)
What is the base radius of the cylinder
12.56 ﹣ 3.14 ﹣ 2 = 2 (CM)
Volume reduction
2 × 2 × 3.14 × 6 = 75.36 (cm3)

The relationship between the earth, the moon and the sun

The earth, the moon and the sun are simply: the moon is the only natural satellite of the earth, and they constitute the Earth Moon system, belonging to the planetary satellite system. The earth is one of the eight planets in the solar system. According to the order from near to far from the sun, it is the third one

1 g of air, air density is 1.29 kg / M cubic, what is the volume of CM cubic?