第1題 a, b, c, d are suspects in a case of corruption. It is now known that: (i) At least one of the three persons other than d is guilty. (ii) If d is guilty, then either b or c is not guilty. (iii) If b or c is guilty, then so is a. (iv) If two or more people are guilty, then d is one of them. Questions: Who is definitely guilty? If either both b and c are guilty or neither of them are guilty, what conclusion can be drawn?

第2題 Four staff members (White, Gray, Brown, Black) attended a training course on identifying counterfeit bank notes. The instructor asked them to inspect three one-thousand-dollar notes. Mr. White said, "The first note is genuine. The third one is counterfeit." Mr. Gray said, "Both the second and the third notes are counterfeit." Mr. Brown said, "The first note is geunine. The remaining notes contain one counterfeit one and one genuine one." The instructor was very annoyed, and said, "The answer of everyone is half correct and half wrong! The success rate is the same as random guessing!" Mr. Black sat in repose with his eyes closed. He has not looked at any of the three bank notes. (But he has studied logic in college with the greatest attention.) He gave all the correct answers without opening his eyes. Can you do the same?

第3題 There are three boxes, A, B & C, only one of which contains a treasure. On each of them is engraved a statement. These boxes are made either by Freyr or by Loki. Boxes made by Freyr always have true statements engraved on them, whereas boxes made by Loki always have false statements engraved. The statements on the three boxes are as follows: A: "The treasure is in Box B." B: "Exactly one of these boxes is made by Loki." C: "None of these boxes is made by Freyr." Questions: Which box contains the treasure? Which box(es) is/are made by Freyr and which by Loki?

煙花

2012-01-08 22:57

用戶被禁言,該主題自動屏蔽!

jimmy

2012-01-08 22:57

有冇中文版呀

fatman

2012-01-08 23:02

Logic Puzzle 係會唸爆頭的

reve

2012-01-08 23:07

不如幫你翻譯，跟住每條200啊？

蕃薯廠

2012-01-08 23:14

第2題似乎係2真, 1,3 假

人人都岩一半錯一半, 所以:

MR. GRAY 話2同3都假, 咁即係一真一假; 即係MR. BROWN 話2, 3 一真一假係岩, 咁即係1係假; MR. WHITE 話1真係錯既, 咁即係3假係岩既 所以有以上結論

Pre

2012-01-08 23:17

咩題目來的

joN3

2012-01-08 23:28

第一條A 一定中

ABCD 無可能 DUE TO ii d有份 bc 事旦一個無事 b/c 事旦一個係 a 都有份 due to iii /唔洗解 b.c 都無事 a 一定有事 due to i /at least one of 3 2 ppl 有事先有機會有d 即係 d未必有事喇

so a 係 conc. if one of b,c takes part ,d also takes part if not , d neither

thmscpl

2012-01-08 23:44

第3題 Ans: box B contains the treasure box A made by Freyr -->"The treasure is in Box B." TRUE box B made by Freyr -->"Exactly one of these boxes is made by Loki." TRUE box C made by Loki --> "None of these boxes is made by Freyr." FALSE

thmscpl

2012-01-08 23:56

第2題 ANS: #1 counterfeit, #2 genuine, #3 counterfeit Mr. White said, "The first note is genuine FALSE --> #1 is counterfeit. The third one is counterfeitTRUE --> #3 is counterfeit." Mr. Gray said, "Both the secondFALSE --> #2 is genuine and the third notes are counterfeitTRUE --> #3 is counterfeit." Mr. Brown said, "The first note is geunineFALSE --> #1 is counterfeit. The remaining notes contain one counterfeit one and one genuine oneTRUE --> #2 is genuine & #3 is counterfeit."

thmscpl

2012-01-09 00:06

第1題 a, b, c, d are suspects in a case of corruption. It is now known that: (i) At least one of the three persons other than d is guilty. (ii) If d is guilty, then either b or c is not guilty. (iii) If b or c is guilty, then so is a. (iv) If two or more people are guilty, then d is one of them. Questions: Who is definitely guilty? If either both b and c are guilty or neither of them are guilty, what conclusion can be drawn?

According to (i) and (iii), a must be guilty! because: (i): if a is guilty --> a is guilty if b is guilty --> (iii) --> a is guilty (same for c) conclusion: a is always guilty!!

If either both b and c are guilty or neither of them are guilty, what conclusion can be drawn? I. if b&c both guilty --> (iv) d is also guilty --> contradict (ii) conclusion: b&c cannot be both guilty II. neither of them are guilty --> (i) a is guilty, d=?

thmscpl

2012-01-09 00:16

引用第7樓joN3於2012-01-08 23:28發表的“”: 第一條A 一定中 ABCD 無可能 DUE TO ii d有份 bc 事旦一個無事 b/c 事旦一個係 a 都有份 due to iii /唔洗解 b.c 都無事 a 一定有事 due to i /at least one of 3 .......

條題目應該咁解......... If eitherboth b and c are guiltyorneither of them are guilty, what conclusion can be drawn?

joN3

2012-01-09 01:02

引用第11樓thmscpl於2012-01-09 00:16發表的“”: 條題目應該咁解......... [表情] If eitherboth b and c are guiltyorneither of them are guilty, what conclusion can be drawn?