Who can help me with the 100 of the small promotion junior high school math papers

1.There are 6 liters of water in a cylindrical container A, and a cylindrical container B is empty. Now fill both containers with water at the same rate of liters per minute.

After 8 minutes, the water surface is the same high, and the radius of the bottom surface of container B is known to be 10 cm. (Take 3) "Equation + Answer".

The height is the same, the ratio of volume is the ratio of the base area, the volume of A: 6+

Volume of B: Base area of B: *10*10=300

18:12 = Base area of A: 300

The base area of the nail = 450 cm.

2.For a project, it takes 8 days for A to complete alone, and 10 days for B to complete alone, and two people can complete one-fifth of all in one day.

3.The number of A = 2 * a * 5, the number B = 2 * 5 * a * 7, the greatest common divisor of A and B is 30, then his least common multiple is (210).

4.The number of students who fail to meet the physical education standards in a school is one-ninth of the number of students who meet the standards, and the physical education compliance rate of this school is (90)%.

5.Master Li made 50 parts, and the pass rate of his parts was between 84% and 96%, so Master Li made at least (42) qualified parts.

and c are both two-digit natural numbers, the digits of a and b are 7 and 5 respectively, and the ten digits of c are 1, and if they satisfy the equation ab+c=2005, a+b+c equals (102).

Here's how to solve it:

The distance between the two towns is 2x km.

Then: before the first encounter, the speed of the car is faster than the tractor = (x+15) (x-15) After the first encounter, the speed of the car is faster than the tractor = (x-15+2x-30) (15+x-30)=3

So: [(x+15) (x-15)]*6 5)=32(x+15)=5(x-15).

3x=105

x=352x=70

Learn from others. Learn together.

Then it is recommended that you go to the cram school for elementary and junior high schools.

First decompose the prime factors of the two results, 255 = 5 * 3 * 17, 365 = 5 * 73 can be known, the multiplier is 5, the number before the pony is multiplied is 51, the little tiger is 73, the ten digits of the pony are correct, and the single digit of the little tiger is correct, so the multiplier is 53

So the result is 265

I don't agree with the common factor, because there may be a common factor in the two multipliers that are mistaken by the pony and the tiger.

When Pony and Tiger do a multiplication problem, Pony misreads the number in the multiplied unit, and Tiger misreads the number in the multiplied digit. The pony scored 255 and the tiger scored 365The correct product of the original question is (

Then, 110 and prime multiplication can only be written: 11 5 2 because 110 is a loose guess multiplied by a multiplier, considering that it is elementary school mathematics, it should be an integer.

Then, 365 and punch 255 divided by 11 or 2 cannot be divided.

The multiplier can only be 5

Then the multiplier written by Pony is: 255 5=51, and Tiger is 73, so the correct multiplier is: 53

so:53×5=265

Solution: Let the distance from P to B be x meters, the first time to walk (540+x) kilometers, the second time to walk 2 (540-x) kilometers, the third time to meet car A in place A, to walk (540+x) kilometers, (as can be seen in the drawing).

Until the third meeting of the two cars, car B has traveled a total of 540 + x + 2 (540-x) + 540 + x = 2160 kilometers.

A: Until the third meeting of the two cars, car B has traveled a total of 2,160 kilometers.

I'll provide an idea of whether it's correct or not.

A and B depart from A at the same time, and the first meeting is B to B, and when A has not yet arrived at B, the second meeting is that B has returned to A and then to B, and A has arrived at B and is on the way back to A.

The second encounter and the third encounter are equivalent to the reverse process from the departure to the first encounter, so when they meet the third time, they are both at the starting point. The final answer was 540 4 2160 km.

If the velocity of A is x and the velocity of B is y, then ap x=(1080-ap) y,2(540-ap) x=2ap y. y=2x, ap=360, pb=180.