Help solve a 6th grade math problem, help solve a 6th grade math problem

Sweat... What is the answer on the first floor?

Solution: Knowing from the meaning of the question:

Perimeter of the outer edge of the wellhead = 2 * radius of the outer edge of the wellhead *

Therefore, the radius of the outer edge of the wellhead = the perimeter of the outer edge of the wellhead 2* = 1 meter.

Therefore, manhole cover area = 2 * * square of the radius of the outer edge of the wellhead = 2**1 = square meters.

Stone area = 2 * * radius of the outer edge of the wellhead + 2) square - manhole cover area = 2* * 3 square meters.

Because one car can transport 12 square meters.

So, to transport: the car. Square metre.

So, at least 4 carts are transported.

A: The area of the manhole cover is square meters.

Spread a 2-meter-wide gravel floor and transport at least 4 carts of stones by trolley.

Note: 3 2 is the square of 3... The square can't be typed...

The circumference of the wellhead is: 2 r=

r=1The face value of the wellhead is: r squared=, because the manhole cover is bigger than the wellhead, so the area of the manhole cover is larger than the area of the wellhead, so the face value of the manhole cover is.

Spread two meters of stones along the edge of the well, so the r of the wellhead plus stones is 1 + 2 = 3 The area of the stones laid = the area of the wellhead plus the stones - the area of the wellhead.

Divided by 12 is equal to, because the stone cannot be laid without being transported, according to the actual situation, it should be transported in three cars.

1) The area is square meters).

2), so at least 3 cars are transported.

100 5 4, B has a speed of 80 meters.

In 5 minutes, A walked 5*100=500 meters, and B walked 400 meters.

900 3 5 = 1500 meters.

Answer: 1500 meters.

According to the inscription, A and B complete 1 10 of the project every day, B C completes 1 12, A C completes 1 15, then two A, two B, and two C complete the project every day

1 10 + 1 12 + 1 15 = 15 60 = 1 4 It can be concluded that A, B and C can complete the project every day

It can be concluded that C can complete the project every day

1 8 - 1 10 (the amount completed by A and B) = 1 40 So C does it alone, and it takes :

1 (1 40) = 40 (days).

If the problem of the quantity of work for three people is given, you can try to add it up, so that you can get the amount that each person does twice (day), and then divide it by 2 to get the amount that all people complete together, and then subtract two of them to get the other one.

12+15=27 is the time it takes for A and B to cooperate to complete two tasks 27, while A and B share 10 days to complete the task, so C takes 27-10=17

It's cumbersome to understand without solving for unknowns.

A and B do 1 10 a day of engineering, B C does 1 12 a day, C A does 1 15 a day A does 1 10-1 12 = 1 60 more than C every day.

The amount of work done by two C's every day is C-A minus 1 60 more than C's daily work, that is, 1 15-1 60 = 1 20, and one C is 1 40, and it takes 40 days to do it.