1, there are five children, Xiaoli, Xiaomei, Xiaoxing, Xiaozhen and Xiaolong, playing together, and some children have mud on their foreheads. Obviously, every child can only see if there is mud on other people's heads, but can't see if there is mud on his own head. Children with mud on their heads can only tell lies, and children who can only tell lies must have mud on their heads. Similarly, a child without mud on his head only tells the truth, and a child who only tells the truth must have no mud on his head. Known:
Xiaoli said: I saw three people with no mud on their heads and one with mud on their heads.
Xiaomei said: I saw four people with mud on their heads.
Xiaoxing said: I saw four people with no mud on their heads.
Xiaolong said: I saw one person with no mud on his head and three people with mud on his head.
Therefore, the following statement must be correct:
A. there is no mud on Xiaoxing's head.
B.there is no mud on Li and Zhen's heads.
C. Xiaomei has mud on her head.
D. Xiaozhen and the small faucet are covered with mud.
2. Four fans predicted the matches of several teams before a game was promoted. They paid more attention to two of them and made the following predictions respectively:
Fang said: If Team A can't get in, then Team B can't get in.
Bai said: No matter whether Team A can advance or not, Team B can't advance.
Xia said: Team B can advance, but Team A can't.
Deng said: I don't think these teams can advance.
The result of the game proved that only one of the four fans' predictions was correct.
According to the above, which of the following must be true?
A. Bai's prediction is correct
B.deng's prediction is correct.
C If Team A can advance, then Party A's prediction is correct.
D If Team A can't advance, then Party A's prediction is correct.
202 1 community workers walking test simulation questions 300 reference answer 3
1, answer C. Observing this example, the stem information tells us that five children, the child with mud on his head tells lies, and the child without mud tells the truth, which shows that this is a simple logical question of truth and falsehood. When encountering this kind of problem, because there is no definite information in the stem information, we can solve the problem in a hypothetical way when the truth is unknown. Observe what these four children say and find out which one is relatively suitable for hypothesis. What Xiaomei and Xiaoxing said is relatively simple and less likely. Judging from these two children, hypothesis is more helpful to solve the problem. Then we can assume that Xiaomei is a child with no mud on her head, which means what Xiaomei said is true. Therefore, except Xiaomei, all the other children have mud on their heads, and all the other children tell lies. Substituting this situation into what other children said, Xiaoli should see that Xiaomei has no mud on her head, and all other children have mud, that is, one has no mud and three have mud, which is inconsistent with what he said. It can be seen that what Xiaoli said is indeed a lie, which conforms to the hypothetical situation. Xiaoxing should also see that Xiaomei has no mud on her head, and other children have mud, that is, one has no mud and three have mud, which is inconsistent with what he said. Therefore, what Xiaoxing said is indeed a lie, which is also in line with the hypothetical situation. Xiaolong should also see that Xiaomei has no mud on her head, and all the other children have mud, that is, one has no mud and three have mud, just like he said. Therefore, Xiaolong's words are true, contrary to the hypothetical situation. Substituting other children's words for verification, we can know the hypothetical situation: Xiaomei has no mud on her head, and telling the truth can't be established. It can be concluded that Xiaomei should be a child with mud on her head and telling lies. Compared with the options, item C meets the requirements.
2. Answer C. After reading the question, you can quickly judge whether the purpose of the question is true or not, so naturally think of our formula at this time? One search, two rounds, three returns? . Find the contradiction first, Fang: non-A? Non-b; Xia: It's not A and B. So Fang and Xia are true or false. The stem also tells us that only one prediction is correct, so the truth appears in Fang and Xia, so both Bai's words and Deng's words are lies. Let's rule out A and B first. If it's not true, it's certain that Team B has advanced. But did team a make it through? We don't know, we need to discuss it in different categories: ① When Team A is promoted, both Party A and Party B are promoted at this time, which shows that Xia's prediction is wrong. Fang and Xia are contradictory, so Fang's prediction is correct. ② When Team A didn't enter, Team B did, and Team A didn't, indicating that Xia's prediction was correct. Fang and Xia are contradictory, so Fang's prediction is wrong. Combining ① and ②, C is correct. So, the answer to this question is C.
?