Mathematical reasoning questions, simple mathematical reasoning problems

First of all, their sisters' names are Xiaoqing, Xiaoyu and Xiaojuan. According to the two brothers and sisters are not allowed to be together, as well as the conditions of the first game, Xiao Ming and Xiao Qing are definitely not brothers and sisters, then his sister may be Xiao Yu or Xiao Juan, and Wang Li's sister is not Xiao Yu, his sister may be Xiao Qing or Xiao Juan. In the second game, Wang Li and Xiaojuan were matched, so his sister could only be Xiaoqing.

And in the second game, Xiao Ming and Xiao Qiang's sister matched, it must not be with Xiao Qing, it should be Xiao Juan or Xiao Yu, but at this time, Xiao Juan is matching with Wang Li, so Xiao Ming can only match with Xiao Yu, so it is certain that Xiao Ming's sister is not Xiao Yu, but can only be Xiao Juan; Xiaoqiang's sister is Xiaoyu.

Conclusion. Xiao Ming's sister is Xiao Juan, Xiao Qiang's sister is Xiao Yu, and Wang Li's sister is Xiao Qing.

From "Xiao Ming and Xiao Qing to Wang Li and Xiao Yu", it is concluded that Xiao Qing is the sister of Xiao Qiang or Wang Li, and Xiao Yu is the sister of Xiao Ming or Xiao Qiang;

From "Wang Li and Xiao Juan's sister to Xiao Ming and Xiao Qiang", it is concluded that Xiao Juan is Xiao Ming or Xiao Qiang's sister, and Xiao Qiang's sister is not Xiao Juan;

So it can be launched: Xiaoqiang's sister is Xiaoyu, then Xiao Ming's sister is Xiaojuan, and finally Wang Li's sister is Xiaoqing.

This kind of problem can be sent with charts, which will be seen clearly and easy to solve.

Wang Li: Xiaoqing.

Xiao Ming: Xiao Juan.

Xiaoqiang: Xiaoyu.

Let's start by assuming A is a demon. "Between c and b, at least one of them is an angel. "False.

b c are all demons. "c and a, at least one is a demon. "False.

a c are all angels. (contradiction!!!Conclusion.

A is not a demon, i.e. A is an angel. Let's say B is a demon. "c and a, at least one is a demon.

False. a c are all envoys of the heavens. (no contradiction) Conclusion:

A c is an angel and b is a demon. Suppose B is an angel. "c and a, at least one is a demon.

True. A has been certified as an angel. c is a demon.

No contradiction) Conclusion: A B is an angel and C is a demon. Summary:

There are 2 possibilities A c is an angel and B is a demon. A B is an angel and C is a wicked sliding demon. In either case, the total number of angels is 2.

Let's analyze what they said first, I don't know if I'm wrong in my analysis. I'm analyzing the department if there is at least one angel system fake.

There is at least one demon in the Governor. Let's hope that's right. If A tells the truth and B also tells the truth, then only C is a demon If A tells the truth and B tells a lie, then only B is a demon If B tells the truth and A tells a lie, then A and C are both demons So according to my own analysis.

It is possible to tie one or two angels.

2, if c tells the truth, c is an angel c and a, at least one is a demon, that is, a if c is a lie, c is a demon c and a, at least one is a demon, a can be an angel 2008-03-04 19:50:33 Added:

Between c and b, at least one of them is an angel, i.e., two can be angels at the same time.

There should be two.

For if a is an angel, then b or c is an angel.

If b is an angel, then a or c is an angel, and a demon is obtained by attacking the ching.

So A and B are not demons.

So C is the devil and there are two angels! I thought of it myself.

Not necessarily married! Reference: me

1. Mathematical reasoning. If you are given a sequence of numbers, but one of them is missing, you are asked to carefully observe the arrangement of the sequence, and then choose the one you think is the most reasonable from the four options to fill in the gap and make it conform to the arrangement of the original sequence.

Please start answering the questions:

Is this the case? If you need it, you can leave an email address and send it to you.

From the 5 piles in order 12345 respectively take 12345 to weigh the total weight, and the result is compared with the multiple of 15, the less is the first pile.

For example, the weighing result is 28, and the multiple of 15 closest to 28 is 30, and 30-28=2, that is, the second pile is false.

Proof: Assuming that the xth pile is false, according to the order of taking, we can know that x are taken in this pile, each of which is 1 gram less than the standard weight, and a total of x grams is missing, that is, the weighing result plus x is (1+2+3+4+5)=15 true weights, each of which is really weighed a, and 15a-weighs a few less x is a few.

Divide into 5 piles, marked 1, 2, 3, 4, 5

Take 1 in the first pile, 2 in the second pile, 3 in the third pile, 4 in the fourth pile, 5 in the fifth and then on the scale. There are a total of 15 pearls on the scale.

Let a pearl be x grams, and if all are true, it will be 15x grams.

Suppose the m pile is fake, and m pearls are taken out in the m pile, and the fake one is 1 gram more than the real one, so there are m grams more.

Then the total weight is 15x+m

Then divide the weight by 15, which can be written in the form of the fraction x+(m 15).

Regardless of the previous x, the number of m on the numerator means that the first pile is false.

To assign several of Zhao, Qian, Sun, Li, and Wu to perform a certain task, the following conditions should be taken into account when assigning:

1, if Zhao goes, then the money will also go.

2. Lee, at least 1 person went in the middle of the week.

3, Qian and Sun went and only went to 1 person.

4, Sun and Li either go or don't go;

5, if Zhou goes, then Zhao and Li will go, and ask who should go?

From the five piles, take one to five pearls and record them. Weigh the weight with a table scale, count the weight, divide the weight by fifteen, see how many the remainder is (must be an integer), and the remainder is the big pile of a few pearls, which is a fake pearl.

Take two in the first pile, and take four in the second pile......Take ten seeds in the fifth pile, put 2+4+6+3 on one side, and put 5+10 on the other.

Extrapolated from weight.

I understand it this way, you can first number five piles of pearls 12345 each pile take a pearl on the scale (each one corresponds to the corresponding 12345), and then take off one by one, I think the one that reduces the weight the most when taking off the corresponding pile number is a fake pearl.

Take 1 of each of the 5 piles to weigh.

A: Draw B: Read a book C:

Washing hair D: Manicure It can be seen from the above conditions: ABC is not manicure, so D must be manicure and then A is not manicure, nor is he reading; So it can only be washing hair or drawing, and if A is not drawing, D is not manicure; And it has been concluded that D is in manicure, so A is drawing.

c is neither reading nor manicure; So C can only be painting or washing hair, and A is drawing, so C is washing hair.

Finally, B is reading a book.

Suppose there were x tons.

Column Equation: Solve the equation: x=1080

Draw a ** as follows:

Manicure] [Hair washing] [Drawing] [Reading] A x x

b x xc x x

D x xa, b, and c are not manicures, so only D is manicures, A, C, and D are not reading, then only B is reading, and now only washing hair and drawing, looking at A and C, because it is mentioned in 3 that if A is not drawing, then D is not manicure; And D is manicure, so A is drawing, so C is washing hair.

A draws, B reads, c washes hair, and ds manicures.

In the first question, you list a, b, c, d, and 4 behaviors, and then connect the things that a, b, c, and d might engage in with a line. Then take a to make two assumptions, and then the answer is deduced. The answer is:

A is drawing, B is reading, C is washing hair, D is manicure.

The second question assumes that the original total amount is x tons, then.

x=1080

A is washing hair, B is reading, C is drawing, and D is manicure.

Assuming that there are x tons of this shipment, we get the equation x ( x=1080

A draws and b. reads.

c shampoo d manicure.

A draws, C washes hair, B reads, D manicures.

To sum up, A, B, and C are not manicures, so only D is manicures, A, C, and D are not reading, then only B is reading, and now only shampooing and drawing, looking at A and C, because it is mentioned in 3 that if A is not drawing, then D is not manicure; And D is manicure, so A is drawing, so C is washing hair.

Number in parentheses: 315....

Method: The relationship between the third number and the first two numbers is, multiply, add, multiply, add.