There are two people, A and B. Among them, A only tells lies and doesn't tell the truth. B only tell the truth, not lies. But when they answer other people's questions, they just nod and shake their heads to show that they don't talk. One day, a man was faced with two roads: Road A and Road B, one leading to the capital and the other to a small village. At this time, there are two people standing in front of him, A and B, but he doesn't know whether this person is A or B, and he doesn't know whether nodding means yes orno. Now, he must ask a question to determine which way leads to Beijing. So, how should I ask this question?
2. What are their occupations?
Xiao Wang, Xiao Zhang and Xiao Zhao are good friends. One went into business, one was admitted to a key university, and the other joined the army. In addition, they also know the following: Xiao Zhao is older than the soldiers; College students are younger than Xiao Zhang; Xiao Wang's age is different from that of college students. Please infer which of these three people is a businessman. Who is a college student? Who is the soldier?
3. Who did it right?
A, B and C are doing their homework together and have a difficult math problem. When all three of them said their solutions, A said, I was wrong. B said: A did the right thing. C said: I was wrong. Ding read their answers, listened to their opinions, and said, one of you three is right and the other is right. Which of them did the right thing?
4. Color of shoes
Xiao Li bought a pair of beautiful shoes. None of her classmates have seen them, so everyone is guessing. Xiaohong said that the shoes you bought won't be red. Cai Xiao said: The shoes you bought are either yellow or black. Xiaoling said: The shoes you bought must be black. At least one of these three people's views is correct and at least one is wrong. What color are Xiaoli's shoes?
5. Who stole the fruit and snacks?
Ms Zhao bought some fruits and snacks to visit a friend. Who knows, these fruits and snacks were stolen by his son, but she doesn't know which one. Therefore, Zhao Nvshi was very angry and questioned his four sons who ate fruits and snacks. The boss said: eaten by the second child. The second said: the fourth stole it. The third said, I didn't steal to eat anyway. Old four said: Old two is lying. Only one of the four sons told the truth, and the other three were lying. So, who stole these fruits and snacks?
6. Who is lying and who has the change?
When my sister came back from shopping, she put some change in her hand in the drawer. However, when she went to buy food with money in the afternoon, she found that there was no change in the drawer, so she called her three sisters and asked them if they had taken the change in the drawer. A said, yes, I went to buy snacks at noon. B said: I saw A take it. C said: Anyway, B and I didn't take it. One of the three people is lying, so who is lying? Who took the change?
7. Where is the night pearl?
A man lost his luminous pearl, so he began to look around. One day, he came to the mountain and saw three huts, namely 1, 2, 3. A woman walked out of these three cabins. 1 The woman in the room said: The night pearl is not in this room. The woman in room 2 said: The night pearl is in room 1. The woman in room 3 said: The night pearl is not in this room. Only one of the three women told the truth, so who told the truth? Which room is the night pearl in?
8. Who got good grades?
Lingling and Fangfang often play together. Once, someone asked them: You two often play together. Which of you did well in the final exam? Lingling said: My grades are better. Xiaohong said Fangfang said: My grades are even worse. At least one of them is not telling the truth. So, which of them did well in the exam?
9. What did they buy?
Xiao Li, Xiao Ling and Xiao Juan go shopping in the shopping center. They all bought what they needed, such as hats, hairpins, skirts and gloves. Everyone bought something different. Someone asked what the three of them bought. Xiaoli said that Xiaoling didn't buy gloves and Xiao Juan didn't buy hairpins. Xiaoling said: Xiaoli didn't buy a hairpin, and Xiao Juan didn't buy a skirt. Xiao Juan said: Xiao Li didn't buy a hat, but Xiao Juan bought a skirt. Half of what each of them said is true and half is false. So, what did they buy?
Who stole the cheese?
Four little mice go out to steal food (they all steal food). When they came back, the patriarch asked them what food they had stolen. Mouse a said, each of us steals cheese. Mouse B said: I only stole a cherry. Mouse C said: I didn't steal cheese. Mouse D said: Some people didn't steal cheese. After careful observation, the patriarch found that only one mouse among them told the truth. Then the following comments are correct:
A. all the mice stole the cheese;
B. not all mice steal cheese;
C. some mice didn't steal cheese;
D. Mouse B stole a cherry.
1 1.
A person stands at a fork in the road, leading to country A and country B respectively. These two GJ people are strange. People in country A always tell the truth, while people in country B always tell lies. There are a countryman and a countryman B: A and B at the intersection, but I don't know their real identities. Now that man is going to country B, but he doesn't know which way to go. He needs to ask these two people. Just one question. How did he judge which way to go?
Answer 1. This person only needs to stand on either road of A and B, and then ask one of them: If I ask him (the other one of A and B) whether this road leads to Beijing, what will he answer?
If a and b both shake their heads, they will go this way; If two people nod, they will go the other way.
Xiao Zhang is a businessman, Xiao Zhao is a college student and Xiao Wang is a soldier. Suppose Xiao Zhao is a soldier, which contradicts the condition that Xiao Zhao is older than a soldier in the title, so Xiao Zhao is not a soldier; Suppose Xiao Zhang is a college student, which conflicts with his younger age, so Xiao Zhang is not a college student; Assuming that Xiao Wang is a college student contradicts the condition that Xiao Wang's age is different from that of college students. Therefore, Xiao Wang is not a college student. Therefore, Xiao Zhao is a college student. According to the conditions, it is bigger than a soldier, a college student is younger than Xiao Zhang, Xiao Wang is a soldier and Xiao Zhang is a businessman.
Suppose c is right, then both a and b are wrong. In this way, A is right, B and C are wrong, which meets the requirements. So, c did the right thing.
4. Suppose Xiaoli's shoes are black, then all three views are correct and do not meet the meaning of the question; Assuming that it is yellow, the first two views are correct and the third view is wrong; Suppose it is red, then three sentences are wrong. So, Xiaoli's skirt is yellow.
It was the third child who stole the fruit and snacks, and only the fourth child told the truth. Assuming that the eldest, the second, the third and the fourth are telling the truth, if they contradict the meaning of the question, they can get the answer.
6.C lied, and A and C both took some. Suppose a lies, then b also lies, which is inconsistent with the meaning of the question; Suppose B lies, then A also lies, which is not consistent with the meaning of the question. Then, the liar must be C. Only when both A and C are changed can they satisfy the problem.
7. 1 The woman in room is telling the truth. The night pearl is in room 3. Suppose the night pearl is in room 1, then the women in rooms 2 and 3 are telling the truth, so they are not in room 1; Suppose the night pearl is in room 2, 1 and the women in room 3 are telling the truth, so they are not in room 2. Suppose the night pearl is in room 3, then only the woman in room 1 is telling the truth, so the night pearl is in room 3.
8. Fangfang. Suppose Lingling is telling the truth, then Fangfang is telling the truth, which is inconsistent with the meaning of the question; Suppose Fangfang is telling the truth, then Lingling is telling the truth, which doesn't match the meaning of the question. Therefore, neither of them told the truth. If you turn what they said upside down, you will find that Fangfang's grades are good.
9. Xiao Li bought a hat, Xiao Ling bought gloves and Xiao Juan bought a skirt.
10. Assuming that mouse A is telling the truth, then the other three mice are lying, which is in line with the premise that only one mouse in the question is telling the truth; Suppose mouse B is telling the truth, then mouse A is lying because they all stole food; Assuming that mouse C or D is telling the truth, these two assumptions can only infer that mouse A is lying, which is inconsistent with the premise. So option a is correct. All the mice stole the cheese.
1 1. If A is a national and telling the truth, ask A: If I ask B which side is safe, which side will he point to? He pointed out that the way B said it was wrong and the other way was right.
If A is a national of B, and the same question is asked to A, because B tells the truth, A will have the opposite answer to B, then the other way is correct.
Topic: Dr. Wang has just applied to open a small pharmacy. He only has one balance, one weighing 5 grams and the other weighing 30 grams. One day, a customer came to the store and wanted to buy100g of precious powder. If you weigh it three times with a weight of 30 grams, then weigh it twice with a weight of 5 grams, * * * 5 times to weigh out 100 grams of powder. But the pharmacy business is busy, and customers hope that the sooner the better. It is impossible to weigh100g at a time. So, can you think of a quick and good way?
Answer: Put 5g and 30g weights at one end of the balance, first weigh out 35g powder, then put 35g powder and 30g weight at one end of the balance, and then weigh out 65g powder, so the total powder is 35+65= 100 (g).
Title: father-son race: Lao Wang and his son Xiao Wang walked back along a circular runway with a diameter of 100 yards to compete. They started from the same place, but at first Lao Wang didn't move at all, and didn't start until Xiao Wang walked one-eighth of the distance. Lao Wang underestimated his son's walking ability, so he walked slowly until he met Xiao Wang on the way. By this time, Lao Wang had walked one-sixth of the distance.
Excuse me: How many times must Lao Wang improve his speed in order to win this game?
Answer: The diameter of the circular runway has nothing to do with the question. When they met, Lao Wang walked the whole distance of 1∕6, while during his walking time, Xiao Wang walked the whole distance of 16∕4, so his walking speed was four times that of Lao Wang. Lao Wang still has 5∕6 miles to run, while Xiao Wang only has 1∕6 miles. So Lao Wang must be at least five times faster than Xiao Wang.
Topic: A happy couple: A and B go shopping in the city. A bought a suit and a hat and spent 15 dollars. B bought a hat, and she spent as much money as A spent on clothes. Then she bought a new dress and spent all their money.
On the way home, B reminded A that his hat was $65,438+0 more expensive than her clothes. Then she said: If we arrange the money for buying a hat and buy another hat, so that my money for buying a hat is 1.5 times that of you, then we both spend the same money.
A said: In that case, how much is my hat worth?
Can you answer a's question? How much did the happy couple spend?
Answer: If X represents the actual price of the hat and Y represents the price of his clothes, then the price of the hat bought by B is also Y, and the price of his clothes is Y- 1. We know that X+Y is equal to 15, so if the 15 they spend is divided into two parts, and one part is 1.5 times that of the other part, then one part must be 6 dollars and the other part must be 9 dollars. Using these data, the following equation can be listed: 9+X 1=6+ 15X. From this, we can find that X is $6.50, that is, the money A spent on the hat. So the money he spent on clothes was $8.50. So I learned that B spent $8.50 on the hat, $5.50 on the clothes, and the total consumption was $29.
7. In a small town, there is a doctor who helps people quit smoking. One day, another smoker came to him for help, so he said to him: a pack of 20 cigarettes, please light the first cigarette, and light the second cigarette after 1 s; After smoking the second one, light the third one 2 seconds later; Smoke the third root, and light the fourth root after 4 seconds; After that, wait for 8 seconds and double the waiting time each time. As long as you follow the rules, I promise you can quit smoking if you can't finish two packs of cigarettes. Do you think that man can really quit smoking if he does what the doctor says?
Answer: It is possible. Just count how long it takes for the 39th cigarette to finish the 40th cigarette. The waiting time is: 5368709 12 seconds = 149 130.8 hours =62 13.8 days, almost 10 years. It's hard not to smoke for such a long time.
Six pears are tied with a five-meter-long cotton thread every other meter. I have eaten a pear now, and I want to use this cotton thread again. I still tie a pear every other meter, and there is no cotton thread left. How should I tie it?
Answer: according to the meaning of the question: six pears, one tied at each end of the cotton thread and four in the middle. A pear has been eaten, so you can't cut off this meter of cotton thread, nor can you distance the four pears in the middle. However, there is no rule that the cotton thread must be straight. Tie one end of the rope to the pear at the other end, and it becomes a circle. Sometimes, the richer the images of things printed in people's minds, the broader and deeper their imagination.
White crane writes numbers: Every time a white crane writes a number symbol (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, *** 10), it needs to be dipped in ink once. * * How much do I need to dip to write the numbers from 0 to 12 continuously?
A: From 0 to 9 * * *, there are 10 digital symbols, while 10, 1 1 2 have six digital symbols. That is to say, from 0 to 12, there are 16 digital symbols. Therefore, cranes need to dip in ink 16 times after writing numbers from 0 to 12.
Lao Li has a well-growing pasture. If he goes to graze 265,438+0 sheep, he can finish the grass on this pasture in 65,438+02 weeks. If you graze 23 sheep, you can finish the grass in 9 weeks. Now Lao Li has 27 sheep. How many weeks can these sheep eat grass?
Answer: It takes six weeks to finish the grass.