When car a runs 80% of the whole journey and car B is 20 km away from 70% of the whole journey, the distance between the two cars is 40 km. How many meters is the distance between car a and car B?

When car a runs 80% of the whole journey and car B is 20 km away from 70% of the whole journey, the distance between the two cars is 40 km. How many meters is the distance between car a and car B?

How many kilometers is the distance between the two places?
（20+40）÷（80%+70%-1）
=60÷50%
=120 (km)
The total length is x km. 80%x-（70%x-20）=40
x=200
The two trains were running from station a and station B at the same time. The first time they met was 40 kilometers away from station a. the two trains continued to move forward at the same speed, and the two trains stopped
You can only solve the problem with one yuan at most
The two trains run from station a and station B at the same time. The first time they meet is 40 kilometers away from station a. the two trains continue to move forward at the same speed. After arriving at the station, the two trains return immediately, and then they meet 20 kilometers away from station B. how many kilometers are there between the two stations?
40 * 3-20 = 100 (km)
A and B two cars at the same time from a, B two opposite each other, the first meeting in a place 50 kilometers away from a, two cars are still at the same speed, each reached the terminal
A and B two cars at the same time from a, B two opposite, the first meeting at a place 50 kilometers away from a, the two cars are still at the same speed, immediately return to the destination, on the way to the second meeting, when the meeting point from B 30 kilometers, then the first meeting from B how many kilometers?
The first time we met, the two cars walked the whole journey together. The meeting point was 50 kilometers away from a point, that is, car a walked 50 kilometers
The second time we met, the two cars walked together for three whole distances. Car a should have gone: 50 * 3 = 150 (km)
30 km away from B, the whole journey is: 150-30 = 120 (km)
Distance from B at first meeting: 120-50 = 70 (km)
Distance between the two places
50×3-30
=150-30
=120 km
The first encounter is 120-50 = 70km away from B. why is the second encounter three times as long as the first one? Suppose the distance is XKM, and the speed of armour is V (x + 30) / v = 50 / V * 3 x + 30 = 50 * 3 x = 150-30x = 120. So 120-50 = 70km, I still don't understand that the first encounter took one whole journey, and the second encounter took three whole journey, so the second encounter time is the second one
Distance between the two places
50×3-30
=150-30
=120 km
When we first met, 120-50 = 70 km from B. why
The distance between a and B is 460 km. The two vehicles AB leave from a and B respectively. Vehicle a runs 60 km per hour and vehicle B runs 48 km per hour
1. The two cars start at the same time, facing each other. How many hours will the two cars meet?
2. The two cars are facing each other. If car a starts half an hour ahead of schedule, how many hours after car B starts, will the two cars meet? How far is the meeting place from Jiadi?
1. Find the encounter time = distance / speed and
That is 460 / (60 + 48) = 115 of 27 (hours)
2. 460-60 * 0.5 = 430 (km)
430 / (60 + 48) = 215 of 54 (hours)
1. 4.2 hours
2. 3.9 hours ﹣ follow up: the formula doesn't only need the answer
There are two cars carrying goods. The goods of a large truck are three times as much as those of a small truck. If the goods of a large truck are transported to a small truck with a weight of 600 kg, the goods of a large truck will be transported to a small truck
How many kilos of goods are there on the big truck?
Primary school mathematics difference problem:
Freight volume of minivan: (600 + 300) △ 3-1 = 900 △ 2 = 450 kg
Freight volume of large truck: 450 × 3 = 1350 kg
Weak question: have you learned binary linear equations now? Question: No
Xiao Ding and Xiao Dong take turns to count from 1 to 10. Each person can count one or two numbers at a time. The winner is the one who counts to 10 at last,
How can Xiao Ding count to win?
123,456,789,10
Divide these numbers in three like this
As long as you can count one, four, seven, ten at a time, you win
Or, on the other hand, if you want to count 10, you should count 7 before, so that Xiao Ding can count to 10 no matter he counts one or two
And so on, if you want to count 7, you have to count to 4,
If we push it further, of course, it will be 1
A and B leave from ab which is 150 km away at the same time. The speed of a is 60 km / h, and that of B is 50 km / h. how many hours later
Are they 29 kilometers apart?
(150 - 29)/(60 + 50)
=121/110
=1.1
A: 1.1 hours later, the two cars are 29 kilometers apart
Time = (150-29) / (60 + 50) = 1.1 hours
1.1 hours
It costs two trucks to transport a batch of chemical fertilizer, 10 times for small trucks and 8 times for large trucks. The total amount of chemical fertilizer transported is 180 tons. The transportation volume of 5 times for small trucks is equal to that of 2 times for large trucks. How many tons each time for large trucks and small trucks?
5 times of small truck is equivalent to 2 times of large truck, 10 times of small truck is equivalent to 4 times of large truck, 10 times of small truck, 8 times of large truck is equivalent to 12 times of large truck, 180 / 12 = 15 tons of large truck, 15 * 2 / 5 = 6 tons of small truck
Xiao Ding and Xiao Dong take turns to count from 1 to 30. Each person can count one or two numbers at a time. The winner is the one who counts to 30
Think about it, first or second? Why?
The latter will win. As long as the latter counts to the divisor of 30 every time, he will be able to count to 30 in the end, such as number a 1, number B 2, 3, number a 4, 5, number B 6
The latter wins
The first way: A and B set out from the two places of AB, facing each other. When they set out, their speed ratio was 4:3
After we met, speed a increased by 10%, speed B slowed down by 20%, so that when a arrived at B, B was still 26 kilometers away from a, the distance between a and B? Second: the average height of students in Grade 5 and 6 of a school was 1.54 meters, the average height of students in Grade 5 was 1.45 meters, the number of students in Grade 5 and 6 was 2:3, the average height of students in Grade 6?
1. From their departure to their first meeting, they go together for a whole journey. Their time is equal, and the distance ratio is equal to the speed ratio
The speed ratio of a and B is 4:3, so the distance ratio is 4; 3 (the number of copies in the whole journey is 3 + 4 = 7)
After meeting, a's speed is 4 * (1 + 10%) = 4.4, B's speed is 3 * (1-20%) = 2.4
A arrives at B, B arrives at 26 kilometers away from A. the journey of the same journey is 26 kilometers less than a whole journey,
The speed ratio of two cars is 4.4:2.4 = 11:6, and the distance ratio is 11:6. The 11 parts of the distance a takes is equivalent to the 3 parts of the distance b takes before meeting. Then the 6 parts of the distance b takes after meeting is equivalent to the original 3 / 11 * 6 = 18 / 11 parts of the distance
26 / (4-18 / 11) = 11 km (each journey) the total distance of 7 routes is 11 * 7 = 77 km
2. The total number of students in the two grades is 2 + 3 = 5, and the average height of the two grades is 1.54 meters, so the total height of the two grades is 2
54 * 5 = 7.7m. Similarly, the total height of grade 5 students is 1.45 * 2 = 2.9m
So the average height of the sixth grade is
(7.7-2.9) / 3 = 1.6m