警察逮捕了四名罪犯– P，Q，R和S。这些罪犯相互认识。他们发表了以下声明：
P says “Q committed the crime.”
Q says “S committed the crime.”
R says “ I did not do it.”
S says “What Q said about me is false”.假设四名被捕者中只有一名犯了罪，而以上陈述中只有一项是正确的。谁犯了罪?
(A) P
(B) R
(C) S
(D) Q答案： (B)
说明：鉴于只有一个人犯罪，只有一个陈述是正确的。
- 如果P是正确的，而Q，R，S是假的：这意味着，
Q committed crime, S did not commit crime, R committed crime, S committed crime.这种情况是不可能的。
- 当Q正确且P，R，S为假时：
Q did not commit crime, S committed crime, R committed crime, S committed crime.这种情况是不可能的。
- 当R是正确的且P，Q，S为假时：这意味着，
Q did not commit crime, S did not commit crime, R did not commit crime, S committed crime.这种情况是不可能的。
- 当S是正确的而P，Q，R为假时：
Q did not commit crime, S did not commit crime, R committed crime, S did not commit crime.这种情况可能意味着R犯了罪。
因此，选项(B)是正确的。
这个问题的测验