1962 AMC 12 第 30 题
先试着解答 1962 AMC 12 第 30 题，然后核对你的答案与精心整理的解答，解答来自 LIVE by Po-Shen Loh。你也可以参加完整限时模拟考试、查看全部 1962 AMC 12 解答，或核对答案。
所有题目均经美国数学协会（MAA）官方合法授权使用。
30.
考虑以下陈述：
和 都为真
为真且 为假
为假且 为真
和 都为假。
为真且 为假
为假且 为真
和 都为假。
其中有多少个陈述蕴含“ 和 都为真”这一命题的否定？
Consider the statements:
and are both true
is true and is false
is false and is true
is false and is false.
is true and is false
is false and is true
is false and is false.
How many of these imply the negation of the statement “ and are both true”?
答案：D
小提示：
只有两个命题都为真时，该否定才不成立
The negation fails only when both statements are true
大提示：
检查列出的四种真假赋值中哪些不是情形
Check which of the four listed truth assignments are not case
解答：
只要 和 中至少一个为假，“ 和 都为真”的否定就成立。这发生在情形 、 和 中，共有 种。
所以正确答案是 D。
The negation of “ and are both true” holds whenever at least one of and is false. This occurs in cases and for a total of
Thus, the correct answer is D.
其他年份的第 30 题
- 1950 AMC 12
- 1951 AMC 12
- 1952 AMC 12
- 1953 AMC 12
- 1954 AMC 12
- 1955 AMC 12
- 1956 AMC 12
- 1957 AMC 12
- 1958 AMC 12
- 1959 AMC 12
- 1960 AMC 12
- 1961 AMC 12
- 1963 AMC 12
- 1964 AMC 12
- 1965 AMC 12
- 1966 AMC 12
- 1967 AMC 12
- 1968 AMC 12
- 1969 AMC 12
- 1970 AMC 12
- 1971 AMC 12
- 1972 AMC 12
- 1973 AMC 12
- 1974 AMC 12
- 1975 AMC 12
- 1976 AMC 12
- 1977 AMC 12
- 1978 AMC 12
- 1979 AMC 12
- 1980 AMC 12
- 1981 AMC 12
- 1982 AMC 12
- 1983 AMC 12
- 1984 AMC 12
- 1985 AMC 12
- 1986 AMC 12
- 1987 AMC 12
- 1988 AMC 12
- 1989 AMC 12
- 1990 AMC 12
- 1991 AMC 12
- 1992 AMC 12
- 1993 AMC 12
- 1994 AMC 12
- 1995 AMC 12
- 1996 AMC 12
- 1997 AMC 12
- 1998 AMC 12
- 1999 AMC 12