Help with the Olympiad math problem, a five point, requiring the list of equations and formulas and

1.Because it is said to be in the middle of the two buildings, there are no flowers on both sides. (It should be like this) 20 3 3 63 (m).

A: The distance between the two buildings is 63 meters.

2.The circular runway is a closed figure. 400 5 80 (face) Answer: 80 bunting is required.

10 8 5 16 (s).

Answer: Ten strikes at 10 o'clock, it takes 16 seconds to strike.

That's it, I hope it helps. ^_

1.(20+2-1)*3=63m.

Face. 3.The interval between each knock is: 8 (5-1) = 2 seconds.

Ten strikes at 10 o'clock, it takes (10-1)*2=18 seconds to finish.

This is the problem of planting trees in elementary schools and sawing wood...

1 20 The tree divides the two floors into 21 spaces, each of which is 3 meters, so it's 63 meters in total.

2 There is only 1 space in front of each bunting, so 400 5=80 buntings are needed (note that it is a circular runway).

The bell strikes at 5 o'clock, so it takes eight seconds for the next four hits, which is two seconds between each one.

So at 10 o'clock, you hit it right away, and you have to hit it nine times at intervals, and it takes 18 seconds.

If you have any problems, you can point them out.

21 3 63 (m) A: The distance between the two buildings is 63 m.

A: 80 buntings are required.

seconds) 10 seconds) A: It takes 15 seconds to finish.

1 (20-1) times 3 = 57

2 400 divided by 5 + 1 = 81

3 8 divided by 5 times 10 = 16

Please give me more points.

The average velocity is (6+4) 2=5 m/s.

A total of 360 2 5 = 144 seconds were run, of which the first 72 seconds were 6 meters and the last 72 seconds were 4 meters.

It takes 360 6 = 60 seconds to go.

It took 144-60=84 seconds to return.

When my father arrived at school, the distance between the two was: 30 * 20 = 600 meters 350 (600 350) = 100

100 20 5 (min).

600 350) 5 50 (m).

A: My son walks 50 meters per minute.

When the father arrives at the school, the distance between the son and the school: 30*20=600 (m)The distance traveled by the son when the father leaves the school and meets the son: 600-350=150 (m).

The father returned with more walks than the son: 350-150 = 200 (meters) Speed difference: 20 meters.

Distance: 200 meters.

Time = distance difference Speed difference = 200 20 = 10 (minutes) The son walked 150 meters in 10 minutes, speed = distance Time = 150 10 = 15 (meters minutes).

A: My son walks 15 meters per minute.

When the father arrives at school, the son leaves the school 30 20 = 600 meters.

When the parent row is 350 meters, the child row is 600-350 = 250 meters.

v Parent: V Son = 350:250 = 7:5

v = 20 (7-5) 5 = 50 m min.

v parent = 20 (7-5) 7 = 70 m min.

A: My son walks 50 meters per minute.

1. Change the "1" in the relative sentence to a movie ticket, then the two sentences with the score rate will become "A's money is 25 6 times that of the movie ticket, and B's money is 5 3 times that of the movie ticket", so that the unit "1" is unified, and "A's remaining money is three more than B's remaining money" means that A is three more than B's total money, and then you can use the idea of difference to solve it, and the column formula is:

3 (25 6-5 3) = yuan) - the volume rate corresponds, and you can directly get the ticket price of the "1" movie.

Do you understand the answer? The next question will be answered later).

1. Solution: Let A and B turn out that the money is x and y

According to the inscription, it can be seen that 6 25*x=3 5*y

x-6 25*x)-(y-3 5*y)=3, so x=5, y=2

2. Solution: Let the original red ballpoint pen be x.

According to the title, the number of ballpoint pens in the box is 4x, then there is (x+8) (4x+8)=5 12

Get x = 73, set up the upper and lower floors, and there are books x and y respectively.

According to the title, x+y=360

x*(1-1/10)=y+1/10*x

x=200, y=160

4. Solution: 1000 * 96% - 1000 * 95% = 105, set Zhao, Qian, Sun, and Li saved money for A, B, C, D, according to the title, get a + b + c + d = 3500

a=1/8*(b+c+d)

b=11/25*(a+c+d)

d=7/29*(a+b+c)

Thus we get c = 12250 9 (if the total deposit is 3600 yuan, then c = 1400).

The first question is correct.

Question 2: Let the ballpoint pen x total number before putting in 4x the total number after putting in 4x+8 red ballpoint pen x+8 The ratio of the two is 5 12 and the solution is x=7

Question 3: Let the upper layer x and the lower layer be 360-x, then there is x-1 10x=360-x+1 10x, and the solution is x=200

Question 4 The essence of apples does not change, what does not change is moisture, the loss of moisture before and after is 96%-95%=1%, and the total weight lost is 1000*1%=10

Question 5 It's too difficult to calculate, I'll come out in a column About it can be known Zhao = 1 8 (money + Sun + Li) 9 8 (money + Sun + Li) = 3500 The following are equivalent to do the math I don't have a pen I can't figure it out.

1. Solution: The money for setting up a movie ticket is x, then A's money is 25 6x, B's money is 5 3x, after buying the ticket (it should be clear whether it is xaa or someone treats), A's remaining money is 25 6x-x=19 6x, and B's money is 5 3x-x=2 3x; According to the inscription 19 6x-2 3x=3You can solve x = yuan, anyway, the process is right, and the final answer is that the night of oral calculation does not know whether it is accurate or not.

Solution: It takes 12 * 4 1 = 48 seconds to get to d, 12 * 4 seconds to c, and the least common multiple of 48 and 40 is 240, that is, after 240 seconds, Xiao Ming arrives at point D for the first time (except for the initial position), and at the same time, Xiao Jie arrives at point C for the first time.

After 240*2=480 seconds, Xiao Ming arrived at point D for the second time, and Xiao Jie arrived at point C for the second time.

The rule is that after 240n seconds (n is an integer, greater than 0), Xiao Ming reaches point D for the nth time, and Xiao Jie reaches point c for the nth time.

Ming passes 12 1=12 seconds to the next vertex, Jie passes 12 seconds to the next vertex, the least common multiple of 12 and 10 is 60 seconds, that is, after 60 seconds, two people reach the apex at the same time, and the 60n second (n is an integer greater than 0) two people reach the vertex for the nth time at the same time.

It can be seen that Ming is 3*12 meters in front of Jie, and the time for Jie to catch up with Ming is 3*12 (seconds, at 180 seconds, Ming is at A, and Jie is also at A, this is the first time to the same apex.

The following process can be seen as Ming is 4*12 meters in front of Jie, and the time for Jie to catch up with Ming is 4*12 (seconds, and the two people reach A at the same time.

The 180th + 240 (n-1) seconds (n is an integer greater than 0, the same below) two people go to a at the same time.

According to 3, the two cannot appear in D at the same time. The two of them start from A at the same time, and the time from Ming to D is 12 1 = 12 seconds, so the time of Ming in D is 12 + 12 * 4N = 12 + 48n seconds, and the time from Jie to B is 3 * 12 seconds, so the time from Jie to B is 30 + (4 * 12 seconds, today it takes 12 + 48n = 30 + 40N, and it gets an integer of n = 9 4 <>, so Xiao Ming is at the point D and Xiao Jie is at the point B does not appear.

1: Let the side length x of the square get the length and width of the original rectangle is x-5 and x-8 and then there is the equation x 2-(x-5)(x-8)=181 to get x=17

2: Girls are 21x higher than the average ( Give these averages to boys i.e.

Therefore, there are 24 boys.

3: Let the divisor be x, then 745-574=10x-9 directly solves x=18 and brings in the remainder 16

4: Observe a total of 66 yuan Therefore, only 1 yuan may be ......Sheet. And because 1 yuan is 2 more than 10 yuan, so 1 yuan must be 6 pieces, 4 pieces of 10 yuan are brought in, and 4 pieces of 5 yuan are brought in.

5: Let B be x after the change, then A is 2x-20 and the equation 2x-20+x=2000+240-160 is solved to get x=700

Before the change, B was 460 and A was 1540

6: There are 56-25=31 people participating in the competition, and the equation 28+27=31+x is solved to get x=24

1. Solution: Let the side length of the square x, then the length and width of the original rectangle are x-5 and x-8, and the meaning of the question can be obtained x 2-(x-5)(x-8)=181, and the solution is x=17

2. Solution: Let the number of boys be x, then (21*, solution x=24.).

3. Solution: Let the divisor be x, then 745-574=10x-9, the solution is x=18, and the remainder is 16

4. Solution: Let ten yuan have x sheets, then one yuan has x+2 sheets, five yuan has 12-2x, from the title can get 10 * x + 1 * (x + 2) + 5 * (12-2x) = 66, the solution is x = 4, so 10 yuan is 4 sheets, 1 yuan must be 6 sheets, and 5 yuan is 4 sheets.

5. Solution: Let B be x after the change, then A is 2x-20, 2x-20 + x = 2000 + 240-160 can be obtained from the title, and the solution is x = 700, so B is 460 before the change, and A is 1540

6. Solution: If there are 56-25=31 people participating in the competition, then 28+27=31+x, and the solution is x=24.

1.Let A x only B (44-2x) 3 be found from the title: 4x+5(44-2x) 3=80 to find a 10 and an 8

2.Let a pair of chess x yuan then a pair of Go x + 3 yuan from the question: 2x+3(x+3)=69 to find a 12 and a 15

3.Let Xiangqi xyuan then Go (84-2x) 4 from the meaning of the question: 2 (84-2x) 4+3x=66 to find a 12 and a 15

4.Let the sheep eat grass x kg then the ox (93-8x) 3 kg from the meaning of the question: 5 (93-8x) 3 + 6x = 111 find the sum of 2 numbers to get 21

5.Let the apple be x yuan per kilogram, then the banana x+ yuan from the question: 5 (x+ find x=3 bananas.

Original Hand play is very tiring.

1) The second time I bought it by 2 times 4 A pens and 6 B pens totaling 88 yuan, compared with the first day, one more B pen and 8 yuan more, so B pen 8 yuan, A pen is (80-5 * 8) 4 = 10 yuan;

2) 69 yuan is equivalent to 5 sets of chess more than 3*3=9 yuan, so Xiangqi ** is (69-9) 5=12 yuan, and Go is 12+3=15 yuan;

3) The practice is the same as 1), multiply the first time by 2 times and then subtract;

4) Multiply the Xiaohong family by 5, multiply the Xiaogang family by 3, and then subtract, the same as 1);

5) 5kg of bananas are more than 5kg of apples, so this 9 yuan is the cost of the remaining 3kg of apples, so apples ** are 9 3 = 3, and bananas ** are 3 + yuan.

1 From the inscription, if you buy 4 A brushes and 6 B brushes for the second time, it will cost 88 yuan.

Therefore, each type of brush is 88-80 = 8 yuan, and the first type is 10 yuan.

2 From the meaning of the title, if you buy 5 sets of chess, it will cost 69-3*3=60 yuan, 12 yuan for each chess set, and 15 yuan for Go.

3 From the inscription, it costs 66 * 2 = 132 yuan to buy 6 sets of chess and 4 sets of Go, so 4 sets of chess **132-84 = 48 yuan.

12 yuan per chess set and 15 yuan for Go.

4 From the meaning of the title to know cattle, sheep and grass.

a 3 8 93

b 5 6 111

then a+b c 8 14 204

d 10 12 222

Informed by C E 4 7 102

d-a f 7 4 129

It is known that 11 cattle and 11 sheep eat 231 kg of grass a day, then 21 kg a day.

5 From the inscription, if you buy 5 kilograms of apples, you will spend less yuan, which is the cost of 3 kilograms of apples.

So apples are 3 yuan, banana yuan.

1.4x+5y=80 Let A be x and B be y2x+3y=40

2.2x+3y=69 assign.

Chess is, Go is y

x+3=y3.2x+3y=69 Let chess be and Go be yx+3=y

Let the ox be x and the sheep y

5x+6y=11

5.5x=8y Let the banana be x and the apple be yx=y+