A and B two cars from both sides of AB at the same time, meet for the first time at 60 kilometers away from a, after meeting continue to move forward, each arrived at the other's starting place immediately On the way back, I met again 40 kilometers away from A. how many kilometers away is ab

A and B two cars from both sides of AB at the same time, meet for the first time at 60 kilometers away from a, after meeting continue to move forward, each arrived at the other's starting place immediately On the way back, I met again 40 kilometers away from A. how many kilometers away is ab

This is the problem of second meeting
You draw the line segment and walk three times when you meet again
In the first time period from starting to the first meeting, the two walked a whole journey; in the second time period from the first meeting to the second meeting, the two walked two whole journey; so the second time period is twice of the first time period
In the first period of time, the first group walked 60km, then the second group walked 2 * 60m = 120km
In addition to the 40 km less traveled and the 40 km started, 3AB = 220 km
Then AB = 110km
A and B are facing each other from ab. when they meet for the first time at a distance of 60 km from a, a runs 60 km,
When they arrive at each other's starting place, they immediately return and meet 40 kilometers away from a place. At this time, the journey of a and B vehicles
The total amount is three times of the whole journey, that is, car a has traveled a total of 60 * 3 = 180 km
AB distance (180 + 40) / 2 = 110 km, the total is three times of the whole journey, that is, car a has a total of 60 * 3 = 180 km, please ask why this place has to take three, Party A and Party B have walked the whole journey respectively, do you know that. After that, the two of them
A and B are facing each other from ab. when they meet for the first time at a distance of 60 km from a, a runs 60 km,
When they arrive at each other's starting place, they immediately return and meet 40 kilometers away from a place. At this time, the journey of a and B vehicles
The total amount is three times of the whole journey, that is, car a has traveled a total of 60 * 3 = 180 km
AB is (180 + 40) / 2 = 110 km. The total distance is three times that of the whole journey. That is to say, car a has traveled 60 * 3 = 180 km in total. Please ask why this place has to take three
After arriving at a and B for the second time, vehicles a and B meet each other 60 kilometers away from a and B at the same time?
80 × 3-60 = 240-60, = 180 km. A: A and B are 180 km apart
A and B start from ab at the same time and run in opposite directions. As a result, they meet for the first time at a distance of 60 km from a, and then they continue to move forward. After arriving at AB, they return immediately. As a result, they meet for the second time at a distance of 40 km from A. how many kilometers is the distance between AB and a?
Party A and Party B met for the first time and had a whole journey
60 kilometers (red)
Party A and Party B met each other for the second time, and had a total of three whole journey
Among them, a performed 2 full courses - 40
Party A and Party B should travel three times as long as one, and Party A should travel 60 × 3 = 180 km
That is to say, two full distances - 40 km is equal to 180 km
So AB distance is (180 + 40) / 2 = 110 km
Let the distance between the two places be s, and the equation is formulated by using the ratio of constant speed and two vehicle speed
S / (S-60) = (s + 40) / (2s-40) gives s = 140 (km)
A: AB is 140 km away.
Suppose that when we meet for the first time, B makes X
The total distance of a and B at the first meeting = 60 + X
The second time we met, a got x + 60 + 40, B got C
(x+60+40)+(x+60+40)=3(60+x)
The solution is x = 20
Total distance = 60 + 20 = 80
Car a and car B travel from a and B at the same time. Car a travels 80 kilometers per hour, while car B travels 60 kilometers per hour. When the two cars meet, it is 40 kilometers away from the midpoint of the whole journey. How long is the whole journey?
(40 × 2) △ 80-60) × (80 + 60), = 80 △ 20 × 140, = 4 × 140, = 560 (km), a: the whole journey is 560 km long
8 / 5 is 4 / 5 more than 1 / 3 of a number. What's the number
Yes (8 / 5-4 / 5) △ 1 / 3 = 4 / 5 △ 1 / 3 = 12 / 5
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8 / 5 is 4 / 5 more than 1 / 3 of a number. This number is (8 / 5-4 / 5) * 3 = 12 / 5
If you don't know, ask me again, I'll be more detailed. I wish you progress in your study!
(8/5-4/5)÷1/3
=4/5÷1/3
=12/5
12/5
Let this number be X
8/5-1/3x=4/5
x=12/5
The distance between a and B is s km. A and B start from a and B at the speed of a km / h and B km / h respectively (see the supplementary explanation)
How many hours will it take for a to meet each other? How many hours will it take for a to reach B after meeting? How many hours will it take for a to reach B after meeting?
Encounter: distance △ speed sum = s △ (a + b)
If only a is walking on the road, it will take s △ a hours. Now a has walked s △ a (a + b) hours, so it still needs (s △ a) - [s △ a + b)] hours
S / (a + b) hours s / A-S / (a + b) hours
The chord length of the line x + 2Y + 1 = 0 cut by the circle (X-2) 2 + (Y-1) 2 = 25 is equal to ()
A. 25B. 35C. 45D. 55
The distance from the center of the circle (2, 1) to the straight line x + 2Y + 1 = 0 is d = | 2 + 2 + 1 | 1 + 4 = 5, and the radius of the circle is r = 5, so the chord length is 2r2 − D2 = 45, so C
A total of 80 tons of goods are transported by 10 large trucks and 20 small trucks. Each large truck carries 3.5 tons more goods than the small truck
How many tons were transported?
Each small truck transports (80-10 × 3.5) / (10 + 20) = 1.5 tons
1.5 + 3.5 = 5 tons per truck
Set each small truck to transport x, large truck to transport x + 3.5
10(x+3.5) + 20x = 80
x =1.5 x + 3.5 = 5
Each truck carries 5 tons, and each truck carries 1.5 tons
Each small truck is set to transport (w-3.5) tons, and each large truck is set to transport w tons
20(W-3.5) + 10W= 80
The solution is: w = 5 tons
A: each large truck carries 5 tons, and each small truck carries w-3.5 = 5-3.5 = 1.5 tons
Let the carrying capacity of each large truck be x and that of each small truck be y
10x+20y=80
x=y+3.5
Finding x = 5 from equations
y=1.5
That is, the carrying capacity of each large truck is 5 tons, and that of each small truck is 1.5 tons
Let each truck transport x tons 20 (x-3.5) + 10x = 80
20x-20*3.5+10x=80
30x-70=80
30x=80+70
30x=150
x=150\30
X=5
Counting. Counting
From a city to a provincial city, a car can travel 80 kilometers per hour, with a distance of 160 kilometers. On an ordinary road, it can travel 40 kilometers per hour, with a distance of 120 kilometers. Which road can save the world?
The highway is 160 △ 80 = 2 hours
The average road is 120 △ 40 = 3 hours
So the highway saves time
If it's a primary school problem, it should be
The first is: 160 △ 40-160 △ 80 = 2 (hours)
The second is: (160 △ 40) × (1-40 / 80) = 2 (hours)
In the first way, you should be able to understand that (160 △ 40) in the second way represents the time it takes to walk on the ordinary road, (40 △ 80) means that 40km / h is half of 80km / h, (1-40 △ 80) that is to say, the proportion of time saved by each unit of high-speed travel compared with that of the ordinary road in the total time, and finally, multiply the time spent on the ordinary road by the unit of distance saving
If it's a primary school problem, it should be
The first is: 160 △ 40-160 △ 80 = 2 (hours)
The second is: (160 △ 40) × (1-40 / 80) = 2 (hours)
For the first type, you should be able to understand that (160 ／ 40) of the second type represents the time required to take the ordinary road, (40 ／ 80) means that 40km / h is half of 80km / h, (1-40 ／ 80) that is to say, every unit distance of high speed saves more time than the ordinary road, Finally, the actual time saved is calculated by multiplying the time spent on the ordinary road by the proportion of the time saved per unit distance to the total time. Put it away
It is known that the distance between AB and a is s km, and a and B start from ab at the same time. If the driving speed of a and B is a km per hour and B km per hour respectively, how many hours later will a and B meet on the way?
The time of meeting is
S ÷ (a + b) = s / (a + b) (hours)
After S / (a + b) hours