What's the meaning of drawing inferences from one instance?

What's the meaning of drawing inferences from one instance?

One thing is listed, and then many other things are known by analogy. Metaphor is to know others by analogy from one thing we know. Description is good at inference, by analogy, good at learning, so that we can know the other
List, list, list

What is the meaning of "decisive" and "indecisive"

Important: Mobile
To enumerate: to enumerate
Generosity: action
Indecision: take it
Draw inferences from one instance

What are the meanings of "Ju" in "numerous" and "infer from one instance"?

There are too many
It can't be listed one by one. It describes a lot of quantity
infer other things from one fact
List one thing, and then analogy to know many other things
Therefore, they all mean enumeration~

Solving several mathematical problems with equations
One is from place a to place B by bike, and the other is from place B to place a by bike. They both go at a constant speed. It is known that they start at 8 am at the same time. They are 36 km apart from each other from 10 am and 36 km apart from each other at 12 noon. The distance between a and B is calculated
2. The original driving speed of a car is 30km / h, now it starts to accelerate evenly, increasing the speed by 20km / h; the original driving speed of a car is 90km / h, now it starts to decelerate evenly, decelerating 10km / h. how long does it take for the two cars to have the same speed? What is the speed at this time?
3. The total length of Beijing Luzhou expressway is 1262 km. A car starts from Beijing and drives at a constant speed for 5 hours, then increases the speed by 20 km / h, then decelerates by 10 km / h after driving at a constant speed for 5 hours, and finally arrives in Shanghai after driving at a constant speed for 5 hours
(1) . calculate the speed of each period (accurate to 1km / h)
(2) According to the map, which section of the road is the car on eight hours after departure? (hint: the total length of the road is 1262 km, and the length of one section of the road can be estimated according to the scale of the map.)
5. (ancient Chinese question) a fast horse walks 240 Li a day, and a slow horse 150 Li a day. A slow horse walks 12 days first. How many days can a fast horse catch up with a slow horse?
6. The running circle of the playground is 400 meters long. A practices cycling, with an average of 350 meters per minute; B practices running, with an average of 250 meters per minute. Two people start from the same place at the same time, how long does it take for them to meet for the first time? And how long does it take for them to meet again

Let a speed be x and B speed be y, we can get x + y = (36 + 36) / (12-10), x + y = 36ab distance between two places: (10-8) * (x + y) + 36 = 108km, let two cars have the same speed after X hours, we can get 30 + 20x = 90-10x solution: x = 230 + 20 * 2 = 70km / h, let the speed at the beginning be x, we can get 5x + 5 (x + 20) + 5 (x + 20-10) = 1262 solution:

To solve several mathematical problems, we need to use equations to solve them
① The cross section of the ingot is square and its side length is 20 cm. In order to forge long cuboids with width of 40 cm, width of 30 cm and height of 10 cm, how long should the ingot be cut?
② In a factory, the number of people in the first workshop is 30 less than 5 / 4 of the number in the second workshop. If 10 people are transferred from the second workshop to the first workshop, then the number in the first workshop is 4 / 3 of the number in the second workshop. Calculate the number of people in each workshop
③ For the first time, more than half of the total length of a wire is used. For the second time, the remaining half is less than one meter, and there are still three or five meters left. Calculate the original length of the wire
The second question is 4 / 5 and 4 / 3, sorry, wrong number However, three people answer the question, and the third question has three answers It's speechless~

1: Suppose: the length of ingot to be intercepted is x? 20 × 20 × x = 40 × 30 × 10, 400X = 12000, x = 302. Suppose: the original number of people in the second workshop is x? The number of people in the first workshop is 5x / 4-30 (X-10) × 4 / 3 = 5x / 4-3

Chickens and rabbits are in the same cage. The number of chickens and rabbits is the same. The total number of legs of the two animals is 168. How many chickens and rabbits are there respectively?

Suppose there are x chickens, according to the meaning of the question: 2x + 4x = 168, & nbsp; & nbsp; 6x = 168, & nbsp; & nbsp; & nbsp; X = 168 △ 6, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; X = 28

There are 100 chickens and rabbits. The number of legs of rabbits is 40 more than that of chickens. How many chickens and rabbits are there respectively?
It's best to do it in a hypothetical or tabular way.

The number of legs of rabbit is 40 more than that of chicken, so the number of feet of chicken is only half of that of rabbit, so the number of feet of chicken is twice that of rabbit in the same part
40 △ 4 = 10
So there are 10 more rabbits than half of the chicken
There are (100-10) / (1 + 1 / 2) = 60 chickens
There are 100-60 rabbits = 40

Three pens are three yuan more expensive than five ballpoint pens. The price of each pen is twice that of each ballpoint pen,
How much is each pen and ball point pen
There are eight more boys than girls in our class, and the number of boys is 1.4 times that of girls
How many boys and girls

Suppose the unit price of ballpoint pen is x, then the unit price of pen is 2x
3×2x－5x=3
x=3
Pen: 2x = 2 × 3 = 6 (yuan)
Question 2: set X for girls and 1.4x for boys
1.4x－x=8
0.4x=8
x=20
Male: 1.4x = 1.4 × 20 = 28 (person)

Xiao Ming's home is 3000 meters away from school. He starts from home by bike at 7:20 in the morning. He travels 250 meters per minute on average and just arrives at school on time. One day, one minute after he starts, he finds that he doesn't have his pencil case with him. He goes home to get it immediately. How many meters per minute does he have to go to return to school to avoid being late? (the time for taking the pencil case is 1 minute)

Let's say x meters per minute is not late. We set out for the first time, then went home to pick up the stationery box. It took 2 minutes before the second time (the speed from the first time to the return was 250 meters per second). We can understand that Xiao Ming set out for school from 7:22. Because it used to take 3000 / 250 = 12 minutes from home

1. A and B leave each other from ab at the same time, and the speed ratio is 7:11. After the first meeting, the two vehicles continue to move forward in the same direction, and return immediately after reaching the destination. When the second meeting, a is 80 kilometers away from B, and how many kilometers is the distance between AB and B
2. A railway station starts to line up a few minutes before the check-in, and the number of passengers per minute is the same. From the start of check-in to the disappearance of the queue waiting for check-in, it takes 30 minutes to open five check-in gates at the same time; it takes 20 minutes to open six check-in gates, and how many check-in gates need to be opened at the same time to make the queue waiting for check-in disappear in 10 minutes?

1. Suppose the total distance is x km, the speed of a is 7V, and the speed of B is 11V. After the second encounter, a runs x + 80, B runs 2x-80, and the time taken to grasp the two is the same, then: (x + 80) / 7V = (2x-80) / 11V, x = 480km
So the distance between a and B is 480km
2. There are y visitors per minute, X at the beginning, and Z tickets per minute at each gate
Formula x + 30y = 5 * Z * 30 1
Formula x + 20Y = 6 * Z * 20 2
Formula 1-2, 10Y = 30z, x = 60z
x+10y=（）*z*10
90z=（9)*z*10
So we need to open 9 gates at the same time