A rare math thinking problem, elementary school students but junior high school students don t know

It's a mindset, and it's easy to think about it, but it's still going to take some time to accept it.

In fact, it's very simple, each of these three people is right to give 9 yuan, and the 2 yuan taken by the clerk is also right, the question is, is the clerk's two dollars from **? At first glance, it was taken from the boss **, but it was still from these three people, so the 25 taken by the boss was exactly 27 yuan, which is equal to the money from these three people.

Nonsense, miscalculated, first of all, 25, there is 3x8=24 less than one dollar, brother, okay to give some points.

The housing cost 25 yuan, and 3 yuan was refunded to the customer, a total of 28 yuan, plus the 2 yuan taken by the clerk, which is exactly 30 yuan.

Because this algorithm is not right. It should be a total of 30 yuan, 25 yuan for the owner, 2 yuan for the clerk, and one yuan for each person for three people.

Oh is a word game, in fact, it was said that 25 yuan a night, the boss should have changed 5 yuan, but only gave 3 yuan, that is, it cost 27 yuan. This is from the point of view of the people staying at the hotel.

From the boss's point of view, he originally charged 30, and finally found 3 yuan to give it, but only got 27 yuan, and the cost was composed of 25 for the hotel fee and 2 tips for the clerk.

The problem lies in the 2 yuan, in the boss is 25 + 2 = 27 yuan, which has nothing to do with the people living in the hotel, anyway, it is the hotel fee, how you distribute it is the boss's own business, if he is willing to give the beggar the same.

Seriously, there are very few normal people who will do this, because normal people don't think that way at all, so there will be no such problems, as for why such problems occur, it is because there are abnormal thoughts, and the normal ones are confused, and the brain can't turn around.

Nowadays, students do too much to add and subtract all the numbers in the problem without analyzing the meaning of the problem.

The key is to read the meaning:

3 people paid 30 yuan, only 25 yuan for the hotel, when the clerk returned the money to the traveler, he took 2 yuan, and divided the remaining 3 yuan equally to the traveler (1 person 1 yuan) "It is already very clear, 3 1 (guest) 25 (the cost of staying in the hotel) 2 (the clerk takes) 30

The back "This is equivalent to 1 person spending 9 yuan, 3 into 9 to get 27, plus the clerk took 2 yuan, a total of 29 yuan, where did the 1 yuan go" is the number addition and subtraction that disturbs people's thinking.

Rather, it should be: 1 person spent 9 yuan, 3 into 9 got 27 25 (the cost of staying in the hotel) 2 (the clerk took).

27 should not be added to the clerk's $2, but should be subtracted from $2 to be the $25 actually received by the hotel.

One yuan is not bad, if you want to say that it is bad, you stole it to buy lollipops.

In the end, it should be subtracted from 2 to calculate the boss's money....His algorithm misleads you.

It's a brain teaser, the 1 yuan is on the person who calculates it.

You are wrong to understand it that way.

That is to say, it is equivalent to 9 yuan per person, 25 yuan, and the boss takes 2 yuan, which is right.

It doesn't seem to be wrong, but you have to pay attention to such a problem: the hotel cost is 25, which can not be divided by 3, and the one yuan is the hotel cost.

The boss said 25 yuan, on average, no one has 8 yuan and 1 yuan left, that is the answer. See clearly.

5 is divided into 3 and 2, and 3 is divided into 3 1s, that is, 5->1+1+1+2, which turns out to be 25->8+8+8+1

That is, 30->9+9+9+2+1

Each person thought it cost 9 yuan, but it actually cost 28 yuan.

First of all, this is logical confusion that makes people dive into a strange circle, "This is equivalent to 1 person spent 9 yuan, plus the clerk took 2 yuan, a total of 29 yuan, where did the 1 yuan go" This sentence is problematic, everyone spent 9 yuan is no problem, 3 into 9 to get 27, three people spent a total of 27 yuan, but it is not right to use 27 to add the 2 yuan taken by the clerk, the 27 yuan paid by three people is including the 25 yuan for the boss and the 2 yuan taken by the clerk himself, 25 + 3 + 2 =30, this formula is correct and reasonable.

Who said that one person spent 9 yuan, obviously three people paid 28 yuan, and 2 yuan was greedy by the clerk, not 30 yuan?

It's just that the title leader has wrapped people in, and 3 into 9 is not right, because 25 yuan and 3 people can't be evenly divided!

Summary. 1.Direct method When the multiple-choice questions are adapted from calculation questions, application questions, proof questions, and true or false questions, you can directly do the calculation questions, application questions, proof questions, and true or false questions, and after determining the answers, you can find them from the options.

Teacher, how to find the coordinates of the second question point A2023 in this question? Is there any pattern?

Finding the coordinates of point A2023 and finding the pattern is an extra homework left for me by our teacher, how to ask for it?

The law is that 2 is the prime and the common ratio is 2 2.

Teacher, can you find the coordinates of a2023? Is there any pattern?

I can find out. The law is that the law is a series of proportional numbers with 2 as the prime and the common ratio is 2 to 2.

So the 2023rd coordinate is 2023-1=20222022 2=1011

It's 1011 root number 2,0

So the coordinates are (1011 2,0).

The tips for answering math questions are as follows.

1.Direct method When the multiple-choice question is adapted from the calculation question, application question, proof question, and judgment question, you can directly do it according to the calculation question, application question, line proof question, and true or false question, and after determining the answer, you can find it from the options.

2.Screening method (elimination method) Remove the false and retain the true, screen out some conclusions that are easier to judge and unsuitable to dig out the meaning, so as to narrow the scope of choice, and then find the correct answer from the rest of the judgment conclusions.

3.Special value method According to the information provided in the answer, select some special field positive situations for analysis, or some special values for calculation, or replace letter parameters with specific values, or treat the proportional number as a specific number with people, and the total key leads, change the general form into a special form, and then make a judgment is often very simple.

The law is that the law is that 2 is the prime minister, and the common ratio is 2 2 proportional sequences "Teacher, I have three bright numbers at the beginning, I don't understand this sentence a little, our teacher hasn't talked about this show to sell some, can you give me a teasing explanation?"

This uses high school knowledge points.

The formula for summing a series of proportional numbers is a formula for finding the sum of a series of proportional numbers.

If the ratio of each term to its preceding term from the second term of a series is equal to the same constant, the sequence is called a proportional sequence.

Summary. Hello, the main difficulty of this question is the understanding of the sentence that the earth takes four times more than Mercury to orbit the sun by 13 days, using the knowledge of primary school, we can set the number of days that Mercury needs to circle the sun as an unknown number, and the steps are as follows: Let Mercury orbit the sun for x days.

4x+13=3654x=352x=88

There are math problems that won't.

Wait a minute. Okay pro.

Among the eight planets in the solar system, the closest to the Sun is Mercury, and the Earth orbits the Sun for 365 days, which is 13 days longer than the time it takes for Mercury to orbit the Sun.

Well. Why haven't you come back yet?

No, I've finished calculating the length of the Tokai Bridge x x =

Hello, the main difficulty of this question is the understanding of the sentence that the earth takes four times more than Mercury to orbit the sun by 13 days, using the knowledge of primary school, we can set the number of days that Mercury needs to circle the sun as an unknown number, and the steps are as follows: Let Mercury orbit the sun for x days. 4x+13=3654x=352x=88

100 5 = 20 100 black sesame seeds are 20 times more than 5 black sesame seeds, then there are 20 of these 100 seeds in the bowl.

100 20 = 2000 capsules.

A: There are about 2,000 sesame seeds in this bowl.

Figure 1: The quadrilateral is added to the circle inside = 3

Figure 2: The quadrilateral subtracts from the outer circle = 1

So quadrilateral=1; Circle = 2. (Or the other way around, quadrilateral = 2, circle = 1, but if you continue to push back, you will find that it is unreasonable, and elementary school students have no negative feelings).

Figure 3: The quadrilateral and the inner triangle add = 6 (the triangle row and the outer diagram are added), so the triangle = 5

Figure 4: The quadrilateral subtracts from the outer triangle = 4 (the triangle row is subtracted from the inner figure) Figure 5: The triangle is added from the outer figure and subtracted from the inner figure, so the result of Figure 5 is 3

It seems that I'm typing too slowly.

Borrow someone else's.

1 solution: 2 (1 10 + 1 12 + 1 15), 2 1 4, 8 (hours);

1-1 10 8) 1 15, (1-4 5) 1 15, 1 5 15, 3 (hours), 8-3=5 (hours);

Answer: C helps A for 3 hours and B for 5 hours

2 solution: Since 14 7 = 2 packs, 35 7 = 5 books, so 1 12 of this batch of books

For: 2 packs + 5 copies

then the approval of 5 12

Yes: 5 2 = 10 packs, 5 5 = 25 copies, that is, 10 packs + 25 copies

Another 10 packs + 25 copies + 35 copies = 11 packs, then 1 pack = 25 + 35 = 60 copies

So this batch of books has a total of:

25 60,1500 (Ben).

A: There are 1,500 books in this batch

3 600, the law of change is.

A and B. Start with 600 600

First time 300 900

2nd time 450 750

3rd time 480 720

So it ended after the 2010th time.

4. The station with the most boarding is the first station, we understand the number of people on the train - the number of people getting off the train, as the increase in the number of people, the first station should increase by 14 people; At the second station, there should actually be 13 trains (there are 13 stations left), 1 need to get off, the actual increase (13-1), and the second station increases by 12; Continue this line of thought; At the third station, there are actually 12 trains, and those who need to get off are (1+1), and there are two stations in front of them to get off; The third station actually increased by (12-2), that is, 10; The fourth station is also launched as 11-(1+1+1)=8; When the increase is 0, it is the time when the number of people in the car is the largest; The sum is: 14 + 12 + 10 + 8 + 6 + 4 + 2 = 56 (pcs).

**: Site:

14 13 12 11 10 9 8 7 6 。。The number of people who board the train at the first stop, and the number of people who are left at the later station.

13 12 11 10 9 8 7 6 。。The number of people who board the train at the second stop, and the number of people who are left at the later station.

12 11 10 9 8 7 6 。。The number of people who get on the train at the 3rd stop, and the number of people who are left at the later station.

11 10 9 8 7 6 。。The number of people who board the train at the 4th stop, and the number of people who are left at the later stop.

10 9 8 7 6 。。The number of people who board the train at the 5th station, and the number of people who are left at the later station.

9 8 7 6 。。The number of people who get on the train at the 6th station, and the number of people who are left at the later station.

8 7 6 。。The number of people who board the train at the 7th stop, and the number of people who are left at the later station.

7 6 。。The number of people who get on the train at the 8th stop, and the number of people who are left at the later stop.

6 。。The number of people who board the train at the 9th station, and the number of people who are left at the later station.

Number of passengers on board:

94 3 minutes.

Let's add a sixth question.

(1) Set C to help A, B's time is x hours and y hours respectively, because A, B and C have been moving, so the three of them have the same handling time, that is, the time of handling experience is (x+y) hours, because to handle a warehouse of goods, A needs 10 hours, B needs 12 hours, C needs 15 hours, so A carries 1 10 of a warehouse goods in an hour, B handles 1 12 of a warehouse goods in an hour, and C handles 1 15 of a warehouse goods in an hourFor warehouse A, the equation can be listed: (x+y)*(1 10)+x*(1 15)=1, and for warehouse b, the equation can be listed:

x+y)*(1 12)+y*(1 15)=1, simplify the two equations to 5x+3y=30 and 5x+9y=60, and x=3, y=5

2) There are a total of y copies of this batch of books, and each pack of x copies, then.

7/12y=14x+35

35+5/12y=11x

That is, y=25x is substituted to get x=60 y=1500

A——— 1,500 copies in total.

94 3 minutes.

6) The topic doesn't seem to be complete, whether the cat barks more or the dog barks more, and the number of times they bark every time they meet in the morning and evening, they don't have to explain, and there is no way to do it.

1 solution: 2 (1 10 + 1 12 + 1 15), 2 1 4, 8 (hours);

1-1 10 8) 1 15, (1-4 5) 1 15, 1 5 15, 3 (hours), 8-3=5 (hours);

Answer: C helps A for 3 hours and B for 5 hours

2 solution: Since 14 7 = 2 packs, 35 7 = 5 books, so 1 12 of this batch of books

For: 2 packs + 5 copies

then the approval of 5 12

Yes: 5 2 = 10 packs, 5 5 = 25 copies, that is, 10 packs + 25 copies

Another 10 packs + 25 copies + 35 copies = 11 packs, then 1 pack = 25 + 35 = 60 copies

So this batch of books has a total of:

25 60,1500 (Ben).

A: There are 1,500 copies of this batch 34

The station with the most boarding is the first station, we understand the number of people on the train - the number of people getting off the train, as the increase in the number of people, the first station should increase 14 people; At the second station, there should actually be 13 trains (there are 13 stations left), 1 need to get off, the actual increase (13-1), and the second station increases by 12; Continue this line of thought; At the third station, there are actually 12 trains, and those who need to get off are (1+1), and there are two stations in front of them to get off; The third station actually increased by (12-2), that is, 10; The fourth station is also launched as 11-(1+1+1)=8; When the increase is 0, it is the time when the number of people in the car is the largest; The sum is: 14 + 12 + 10 + 8 + 6 + 4 + 2 = 56 (pcs) 56

Too tired to write.