The two vehicles run from two places 210km apart at the same time. After 8 minutes and 7 hours, they run 75% of the whole journey. It is known that the speed ratio of the two vehicles is 3:1

The two vehicles run from two places 210km apart at the same time. After 8 minutes and 7 hours, they run 75% of the whole journey. It is known that the speed ratio of the two vehicles is 3:1

The two vehicles run from two places 210km apart at the same time. After 8 minutes and 7 hours, they run 75% of the whole journey. It is known that the speed ratio of the two vehicles is 3:5
210×75%÷7/8×3/（3+5）
=157.5÷7/8×3/8
=157.5×3/7
=67.5 km / h
The speed of a and B is (180 × 7 / km)
3+5=8
The speed of car a is: 180 × 3 / 8 = 67.5 km / h
At the same time, the two cars are 210 km away from each other. After 7-8 hours, they are still 3 / 4 of the distance. The speed ratio of car a and car B is 4:5
According to the meaning of the title
7 / 8 hours, 1 / 4 of the whole journey
That is 1.5 × 210 km = 1.5 × 52 km
Speed sum of a and B = 52.5 / (7 / 8) = 60 km / h
Speed of a = 60 × 4 / 9 = 80 / 3 km / h
According to the meaning of the title
7 / 8 hours, 1 / 4 of the whole journey
That is 210 × 1 / 4 = 52.5km
Speed sum of a and B = 52.5 / (7 / 8) = 60 km / h
Speed of a = 60 × 4 / 9 = 80 / 3 km / h
It is known that the distance between a and B is 300 km, and the speeds of a and B vehicles are 70 km / h and 80 km / h respectively. How long does it take for a and B vehicles to travel in opposite directions from ab at the same time
Let XH meet, and the equation is (70 + 80) x = 300. Can you write a different problem according to this equation
The students in a class are divided into two teams, male and female, to peel peanuts. They need to peel 300 kg. The female team peels 70 kg every day, and the male team peels 80 kg every day. The two teams start to peel peanuts at the same time. How many days can they finish it?
Let X days finish stripping, and the equation is (70 + 80) x = 300
It is known that the distance between a and B is 300 km, and a and B vehicles run from ab at the same time and meet in 2 hours. It is known that car a travels 70km per hour, and the speed of car B is calculated.
Two batches of goods, one 480 tons, 8 cars, 20 cars, 2 524 tons, 10 cars, 6 cars, how many cars are each loaded
Train car 50 tons, car 4 tons
The train car is x tons, the car is y tons,
The equation 8x + 20Y = 480,
10x+6y=524
The solution of the equation is: x = 50, y = 4
The school organized 96 students to visit and give each of them a bottle of mineral water. The unit price of each bottle of mineral water is 2 yuan. If you buy a whole box, you can get 10% discount for 12 bottles in a small box, and 20% discount for 20 bottles in a large box. Please use your brains carefully and design the most economical way to buy only 96 bottles of mineral water
96/12=8
Price = 8 * 12 * 2 * 90% = 172.8 yuan
The distance between a and B is 360 km. The passenger cars and freight cars start from the two places at the same time and travel in opposite directions. Their speed ratio is 5:4?
Because the speed ratio of a and B is 5:4, the distance is directly proportional to the speed, so the distance ratio is 5:4, 5 + 4 = 9, the distance of bus: 360 × 59 = 200 (km), the distance of truck: 360 × 49 = 160 (km). A: when the two cars met, they drove 200 km and 160 km respectively
Given the quadratic equation of one variable KX ^ 2-2x + K ^ 2-k = 0 about X, find the value of K
Because KX ^ 2 -- 2x + K ^ 2 -- k = 0 is a quadratic equation of one variable with respect to X,
So as long as the coefficient K of the quadratic term is not equal to 0,
So the value of K is: K is not equal to 0
If each vehicle carries 3 tons of goods, there will be 5 tons left. If each vehicle carries 4 tons, there will be 5 less vehicles. Question: how many vehicles are there and how many tons of goods?
Set up binary linear equation x cars y tons of goods
4（x—-5）=y
3x+5=y
x=25 y=80
Class 6 (1) students need to buy 48 bottles of Yibao mineral water of the same size to organize activities. The monitor learned that: each box of 10 bottles of mineral water in supermarket a costs 20 yuan, and the price is full
In supermarket B, 12 bottles of the same mineral water are sold for 27 yuan per box. If you buy 4 cases of the same mineral water, 85% of the total price will be paid. If you are the monitor, which supermarket will you go to? Please explain your reason through calculation
Supermarket a: for 5 cases, the amount of money needed is 5 × 20 × 90% = 90 yuan
Supermarket B: for 4 cases, the amount of money needed is 4 × 27 × 85% = 91.8 yuan
Because a uses less money than B, and 2 bottles more, so you should choose a supermarket
A shop to buy 5 cases: 5 * 20 * 0.9 = 90
Store B wants to buy 4 cases: 4 * 27 * 0.85 = 91.8
∵90
The distance between a and B is 360 kilometers. The passenger cars and freight cars leave from the two places at the same time and meet each other after 5 hours. It is known that the speed ratio of the freight cars to the passenger cars is 4:5
Q: how many kilometers did the bus travel when they met?
Speed sum: 360 △ 5 = 72 (km / h)
The speed of passenger car is 5 / 4 times that of freight car, that is 1.25 times
Now it can be solved by the sum multiple formula
Freight car speed
72 ÷ (1.25 + 1) = 32 (km / h)
Bus speed
72-32 = 40 (km / h)