Xiao Ming and Xiao Qiang are both students of Teacher Zhang

The answer should be September 1. 1) First of all, these 10 sets of dates are analyzed, and it is not difficult to find that only the number of days on these two sets of dates, June 7 and December 2, is unique. From this, it can be seen that if Xiaoqiang knows that n is 7 or 2, then he must know the teacher's birthday.

2) Re-analyze "Xiao Ming said: If I don't know, Xiao Qiang definitely doesn't know", and the number of months of the 10 groups of dates is 3, 6, 9, and 12 respectively, and there are more than two sets of dates in the corresponding month, so it is impossible for Xiao Ming to know the teacher's birthday after learning m. 3) Further analysis," Xiao Ming said

If I don't know, Xiaoqiang definitely won't know", combined with the conclusion of Step 2, it can be seen that Xiaoqiang will never know after learning n. 4) Combining steps 3 and 1, it can be inferred that all the dates of June and December are not the teacher's birthday, because if Xiao Ming knows that m is 6, and if Xiao Qiang's n==7, then Xiao Qiang knows the teacher's birthday.

In the same way, if Xiao Ming's m==12 and Xiaoqiang's n==2, then Xiaoqiang can also know the teacher's birthday. That is: m is not equal to 6 and 9.

Now there are only five sets of dates left: "March 4th, March 5th, March 8th, September 1st, and September 5th". And Xiaoqiang knows, so n is not equal to 5 (there are March 5 and September 5), at this time, Xiaoqiang's n (1,4,8) Note: Although there are three possibilities for n at this time, as long as Xiaoqiang knows one of them, he will draw conclusions.

Therefore, there is "Xiao Qiang said: I didn't know it originally, but now I know", for us, we still need to continue reasoning to this point, and the rest may be "March 4, March 8, September 1", 5) analysis "Xiao Ming said: Oh, then I also know", indicating m==9, n==1, (n==5 has been excluded, and there are two groups in March).

If the teacher tells Xiaoqiang that the date is the 2nd or 7th, then Xiaoqiang will know the teacher's birthday. Because there is a corresponding month, these two days are removed.

Xiao Ming said: If I don't know, Xiao Qiang definitely doesn't know. Because the 7th and 2nd are in June and December, respectively.

So the teacher's birthday is not in June and December. Proof: If the teacher's birthday falls in June and December, it does not correspond to the condition

Xiaoqiang definitely didn't know. If the teacher's birthday is in June and December, then this condition should be: if Xiao Ming does not know, Xiao Qiang may know.

Xiaoqiang said: I didn't know it at first, but now I know. Because June and December are excluded.

There are only March 4th, March 5th, March 8th, September 1st, and September 5th because Xiaoqiang said he knew, so March 5th and September 5th were removed. Proof: If the teacher's birthday is still unknown in these two days.

Xiao Ming said: Oh, then I know too. Because March 5 and September 5 are excluded.

There are only March 4th, March 8th, and September 1st left. Because Xiao Ming also said that he knew, he removed March 4th and March 8th. Proof:

If the teacher's birthday is not eligible in these two days, Xiao Ming also knows. Otherwise, he still doesn't know.

Final answer: September 1.

I don't know I don't know I don't know the first sentence and I don't know how to rule out June and December.,I've read a bunch of explanations and it's easy to do.,I want to elaborate in another way.,Maybe it's going to make sense:

It's a beautiful story.

Ming and Qiang are testing each other, and the three sentences are two consecutive temptations and the last sentence is true. Through this dry dialogue, it is set up to push back (note that the number of months and dates that the two of them know are related, and it is easy to disassemble and piece them together separately when we want to, which is why June 4th and December 1st and December 8th can't be put down).

The first sentence is tentatively established: Xiao Ming: 3, 9 Xiao Qiang: 1, 4, 5, 8 or Xiao Ming: 6, 12 Xiao Qiang: 4, 7, 1, 2, 8

When Xiao Ming holds the 6 and 12 cards, Xiao Qiang must touch the 4, 7, 1, 2, and 8 cards. At this time, Xiao Ming didn't dare to say that this Xiaoqiang "certainly" didn't know, because he was afraid that Xiaoqiang might touch the No. 7 and No. 2 cards at this time, and he couldn't be so confident. In other words:

Xiao Ming said, "Qiangqiang, you may be able to know the answer without relying on me" If this temptation is admitted by Xiao Qiang, it means that Xiao Ming has 6 or 12 in his hand.

Zheng push) Xiao Ming has 3 and 9 cards in his hand, and Xiao Qiang must take 1, 4, 5, and 8 cards. At this time, Xiao Ming can say confidently: You definitely can't I don't know You know the answer, you still have to hint at each other a little.

The second sentence is tentatively established: Xiao Ming: 3, 9 Xiao Qiang: 1, 4, 5, 8

Xiaoqiang's heart was secretly cool, and he was full of confidence, so he also tried to "Then I will know the answer", and he actually succeeded again, explaining:

Xiaoqiang's successful test shows that he is not taking 5, because if he takes 5, he doesn't know if it is 3 or 9.

She also knew the summary of the third game: March 4th, March 8th, and September 1st.

March 4 and March 8, and September 1. Xiao Qiang said that he knew that Xiao Ming could actually know by himself, which means that Xiao Ming couldn't be a No. 3 card, because if she took a No. 3 card, she didn't know that Xiao Qiang was holding a 4 or 8.

That is, if two or three sentences are true, I know them once and for all, it means that the vertical March 5th, September 5th, and the horizontal March 4th, and March 8th should be excluded.

So on September 1st, this teacher really showed.

1.Both know the 10 sets of days.

The group of days contains two 4 days, two 8 days, two 1 days, two 5 days, one 7 days and one 2 days (7 and 2 days are key).

3.Xiao Ming knows the month, and Xiao Qiang knows the day.

4.Xiao Ming knows that Xiao Qiang knows the n value, and Xiao Qiang also knows that Xiao Ming knows the M value (nonsense, but this is very important).

Analysis:1The answer can't be and, there is only one 7th and one 2nd, if it is these two days, Xiaoqiang knows the n value, and he will know which day it is at the beginning.

2.Xiao Ming said: If I don't know, Xiao Qiang definitely doesn't know.

Xiao Ming knew that Xiao Qiang knew the n value, but he was sure that if he didn't say it himself, Xiao Qiang would definitely not know the answer, indicating that the day could never be a month that included the 7th and 2nd (he was sure that the months he knew definitely did not include these two special days that would get the final answer as long as he knew the n value), excluding June and December, and the remaining months of March and September.

3.Xiaoqiang said: I didn't know it at first, but now I know.

Xiao Qiang didn't know that "it was impossible to verify the day, and he deduced from Xiao Qiang's words that the months could only be March and September. But he knew the answer, which means that the n-value is unique in March and September, excluding March 5 and September 5.

4.Xiao Ming said: Oh, then I know too.

The answer is only day, day and day. Even Xiao Ming knew that it could only be a day (March contains two days, he can't be sure, and in September there is only one day, he can be sure).

Answer 9/1.

The collocation of m The collocation of n.

a
b:2-12

c
d
e:7- 6

F 1: According to "Xiao Ming said: If I don't know, Xiao Qiang definitely doesn't know", the possibility of m=6 and m=12 is ruled out.

Analysis: If m is , Xiao Ming's choice is 6-4 6-7 12-1 12-2 12-8, but -2 (that is, b and f in the collocation of n) are unique to Xiao Qiang, so there is uniqueness in the options of , therefore, Xiao Ming is impossible to say "definitely" and does not know, he can only say "maybe" and does not know.

2: Exclude the collocation of m after m=6 and m=12).

N ) 7-6) (8-3).

According to Xiaoqiang: he knows, he can rule out n=5, because if n is equal to 5, then there are still two possibilities, and he can't say that he knows the answer.

3: After excluding n=5, the collocation of m is only ) 9-1).

According to Xiao Ming: "Oh, then I know too", m=3 can be ruled out, because there are two options in m=3, which are uncertain. Therefore, m=9

Answer 9/1.

1.First of all, exclude June 7 and December 2, because Xiaoqiang knows that it is 7 or 2, and he can know the answer directly without knowing the month.

2.Xiao Ming said that the meaning expressed after the first sentence is that the number of days in this month that I know has appeared twice, Xiao Qiang replied: Yes, my number of days is not 2 or 7, it is the number of repeated days, which is in line with all dates in March and September, and does not meet in June and December.

3.Date Remaining.

March 4 March 5 March 8

September 1 September 5

Look at the March 5 and September 5 5 repeats, leaving March 4 and March 8 March repeated. Finally September 1 should be this line of thought.

It's September 1, according to"Xiao Ming said: If I don't know, Xiao Qiang definitely doesn't know. ", it is impossible for m to be 12 or 6, because the 7 and 2 in June 7 and December 2 are separate, Xiao Ming can be sure that Xiao Qiang does not know, which means that m cannot be 12 and 6, from"Xiaoqiang said: I didn't know it at first, but now I know. "In this sentence, we know that n cannot be 5, the value of n can be 1, 4, and 8, and the third sentence"Xiao Ming said:

Oh, then I got it, too"It can continue to conclude that the m value cannot be 3, because there are also March 4 and March 8 in March that cannot be determined, that is, the m value can only be 9 in the end, that is, the teacher's birthday is September 1st!

If M is 12, then Xiao Ming can't say that Xiao Qiang definitely doesn't know. Seeing clearly, Xiaoqiang definitely doesn't know. That is, Xiaoqiang can't guess what day it is in December, but if it's December 2nd, Xiaoqiang can guess it, so it can't be December.

There is also the issue that n is 5. If n is 5, then Xiaoqiang still doesn't know which month it is, because there are 5 in March and September.

I have a problem understanding this question! If I don't know, Xiaoqiang doesn't know, how can I rule it out? I know if it's 9! In this sentence, Xiaoqiang can't exclude any number, because there is no date and month in it, only the number of the month and day can be excluded!

It's September 1st.

Because Xiao Ming knows the month, but each month has more than 2 dates, so Xiao Ming definitely doesn't know that the reason why he can be sure that Xiao Qiang doesn't know is because every date in the month he knows has appeared more than twice.

Looking at all the days, you will find that there is only one date on June 7 and December 2, so June and August are excluded.

So there are March 4th, March 5th, March 8th, and September 1st left. On September 5th, after Xiaoqiang reasoned and ruled out, he knew, which means that among the remaining 5, there must be the one with only a unique date.

March 5 and September 5 have the same dates and are excluded.

So there are March 4th, March 8th, September 1st left.

After Xiao Ming reasoned and ruled it out, he knew, so it must be the only month out of the three, so it was only September 1.

I think it's September 1st.

Xiao Ming said: If I don't know, Xiao Qiang definitely doesn't know, then the only value that can exclude n is the month of June and December, Xiao Qiang said: I didn't know either, but now I know, indicating that the n value is not 5, then the answer excludes March 5 and September 5.

Xiao Ming said: Oh, then I know too.

Then it means that his m-value should be 9, because if it is 3, he still does not know which date it is.

September and November are excluded first because they only appear once in this month, and as long as you know m, you can know the birthday. And then it is discharged because it only appears once on the 5th, and if you know n, you will know.

It can be seen that it can only be , one of the three, Xiao Ming, who knows the month, still says that he can't guess it, which means that it is not the only month of July, and at the same time says that Xiao Qiang can't guess it, indicating that the day has appeared twice, that is, the third (if it appears once, Xiao Qiang will know that it is a birthday - the only day) so it is not The answer is March 3rd to choose b

The can't be pulled out, and it's a strange pit.

Mr. Zhang told Xiao Ming about the m-value and Xiao Qiang about the n-value, and Mr. Zhang asked them if they knew what his birthday was.

March 4, March 5, March 8.

June 4 June 7.

September 1 September 5.

December 1, December 2, December 8.

I'll change their conversation to keep the meaning the same, and you'll understand it right away.

Xiao Ming held a number in his hand, glanced at the group of numbers on it again, and said calmly: If I don't know, you Xiaoqiang definitely don't know (the one he holds in his hand must be 3, or 9, because the dates after these two months are repeated).

Xiao Qiang said: Xiao Ming, you are proud, I didn't know it originally, but I know now when you say that. (He couldn't possibly still have the number 5, otherwise he would dare to say this?)

In this way, it can be judged that the number given to him by the teacher is or 8, and he immediately came to his conclusion in his heart, but so far, we don't know whether this number is 8 or not, only Xiaoqiang knows).

Xiao Ming said: Oh, then I also know (here, we excluded two numbers, if the one in his hand is 3, then, he can't determine the final date, only with the number 9, dare to shout confidently, I know, hahahaha).