警方逮捕了四名罪犯——P、Q、R 和 S。这些罪犯彼此认识。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”.假设被捕的四人中只有一名犯了罪，并且上述陈述中只有一项是正确的。谁犯了罪?
(一)
(乙)右
(C)小号
(四)问答案：(乙)
说明：鉴于只有一个人犯了罪，而且只有一个陈述是正确的。
- 当 P 正确而 Q、R、S 错误时：它意味着，
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 正确而 P、R、S 为假时：这意味着，
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 正确而 P、Q、S 错误时：它意味着，
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 正确而 P、Q、R 为假时：这意味着，
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。
所以，选项(B)是正确的。
这个问题的测验