Distress! Some math Olympiad topics, urgent! Olympiad problems

Question 1: Three hours, 15 kilometers away! Answer: The relative velocity is 2 kilometers per hour, 6 2 = 3 hours 3 * 5 = 15 kilometers.

Question 2 Two Turns Answer The relative velocity is 6-4=2 meters per second 400 2=200 seconds 200*4 400=2 revolutions.

Question 3 a+b = 1898 zeros

a*b = 3797 zeros

a b = 3 * a + 2 * b = 1898 zeros

Question 1: A walked for 3 hours, and the distance between AB was 15 kilometers.

Question 2: When B runs two laps, A can overtake B by one lap.

Question 3: a+b=, (1898 zeros after the decimal point) a-b, (1898 zeros after the decimal point).

a*b, (3797 zeros after the decimal point).

a/b＝3．125

3*a+2*b, (1898 zeros after the decimal point).

1, 6 (5-3)=3 hours, 5*3=15 km.

2, Set x seconds, 6x-4x=400, x=200 200*6 400=3 turns.

3, a+b = 1898 zeros

a-b = 1898 zeros

a*b = 3894 zeros

a b = 3 * a + 2 * b = 1898 zeros

6 (5-3) = 3 hours.

AB distance 3*5 15 km.

400 (6-4) = 200 seconds.

4*200 400 2 laps.

a+b=25+8 33 1898 zeros in front

a-b = 25-8 17 1898 0s in front

a*b=25*8 2 front 1900 2-3 0a b=25 8

3*a+2*b=75+16 91 1898 0s in front

If you're in a hurry, you can't just bring it in yourself. Don't be lazy.

The first encounter, the two cars added up and walked 1 times the length of AB, and the total distance of the second encounter was three times the length of AB (car A and car B each walked 1 total distance and then turned around), so the distance traveled by the two cars during the second meeting was three times that of the first time, because car B went a section AB and turned back to 42km, so car B went 54 3-42 = 120km

The second formula is also counted out.

My primary school Olympiad has always been the top in Beijing, and I can try my best to answer any questions.

At the first encounter, cars A and B traveled the full length of AB, and on the second encounter, they traveled three times the total length of AB. Draw a picture of this yourself.

b The distance traveled by the second encounter was three times that of the first 54, and the full length was added to 42, so the full length: 54x3-42 = 120

The distance between the two meeting points is the full length minus the length of the two ends, which is 120-54-42 = 24

Let me explain to you: In fact, it is not difficult, has the whole process of A and B traveled three times the distance between the two places? Then you can think of this whole process as something like this:

Because the speed of A and B is constant, if they walk the S distance, do they meet at a distance of 54km from point B? So you can think of the 3s as if they are repeating the process. In this way, the person who starts from point B has traveled the whole distance of 3*54, and this process is equivalent to S+42 in the title

This 42km is the return distance from point A. So it can be calculated in this way.

If you don't understand, just calculate it according to the speed ratio, it won't be too difficult, the time is the same, the speed ratio is constant, and you can find this value.

The first equation is a simplified equation.

Let the full length be x.

From meeting at a distance of 54 km from place B, it is found that A travels x-54 and B travels 54, and when A and B complete a full journey, the difference in distance is x-54-54. At the second encounter, a total of 3 full journeys were completed, and the difference should be 3 (x-54-54), that is, 3x-54*3

On the way, they met at a distance of 42 kilometers from place A, and according to the above idea, it can be concluded that the difference in their distance after the second meeting is x-24-24

The difference between the two distances is equal, and the equation is listed.

3x-54*6=x-42-42

2x=54*6-42*2

x=54*3-42 (This is where the first equation comes from.) x=120

Hello landlord, set the full length to s, the first time we met: A line S 54, B line 54; The second time they met, A played 2s 42 and B went S 42;The ratio of A and B is equal twice. Both (s 54) (54) (2s 42) (s 42), the solution is 120, so the distance is 24

Very understandable, I hope I can help you, welcome to ask, but I usually have to wait for me to change the computer to answer, I can answer all kinds of primary and junior high school Olympiad questions for you for a long time, if you want to ask me it is best to ask me another question directly.