The following are some statements to test your reasoning ability . Tell whether the conclusions after the word “Therefore” are true ( T ) false ( F ) or uncertain ( U ) . Write your answer on the line before each statement . _ 1 All odd numbers are integrers ( 整 数 ) . Therefore all odd numbers are even numbers . _ 2 There are no dancers that aren t slim and no singers that aren t dancers . Therefore all singers are slim . _ 3 A toothpick ( 牙签 ) is useful . Useful things are valuable . Therefore , a toothpick is valuable . _ 4 Three pencils cost the same as two erasers . Four erasers cost the same as one ruler . Therefore , pencils are more expensive than rulers . _ 5 Class A has a higher enrollment than Class B . Class C has a lower enrollment than Class B . Therefore , Class A has a lower enrollment than Class C . _6 A fruit basket contains more apples than lemons . There are more lemons in the basket than oranges . Therefore , the basket contains more apples than oranges . _7 Taking the train across town is quicker than taking the bus . Taking the bus across town is slower than driving a car . Therefore , taking the train across town is quicker than driving a car . _8.All the tulips in Zoe s garden are white All the roses in Zoe s garden are yellow . Therefore , all the flowers in Zoe s garden are either white or yellow .
The following are some statements to test your reasoning ability . Tell whether the conclusions after the word “Therefore” are true ( T ) false ( F ) or uncertain ( U ) . Write your answer on the line before each statement .
_ 1 All odd numbers are integrers ( 整 数 ) . Therefore all odd numbers are even numbers .
_ 2 There are no dancers that aren t slim and no singers that aren t dancers . Therefore all singers are slim .
_ 3 A toothpick ( 牙签 ) is useful . Useful things are valuable . Therefore , a toothpick is valuable .
_ 4 Three pencils cost the same as two erasers . Four erasers cost the same as one ruler . Therefore , pencils are more expensive than rulers .
_ 5 Class A has a higher enrollment than Class B . Class C has a lower enrollment than Class B . Therefore , Class A has a lower enrollment than Class C .
_6 A fruit basket contains more apples than lemons . There are more lemons in the basket than oranges . Therefore , the basket contains more apples than oranges .
_7 Taking the train across town is quicker than taking the bus . Taking the bus across town is slower than driving a car . Therefore , taking the train across town is quicker than driving a car .
_8.All the tulips in Zoe s garden are white All the roses in Zoe s garden are yellow . Therefore , all the flowers in Zoe s garden are either white or yellow .
题目解答
答案
- F ；句意：所有的奇数都是整数。因此所有的奇数是偶数
整数包括奇数和偶数，奇数和偶数是并列关系，故F。
- T；句意：所有的舞者都很瘦，所有的歌手都是舞者。因
此，所有的歌手都很瘦。逻辑正确，故T。
- T；句意：牙签有用；有用的东西是有价值的。因此，牙签
是有价值的。逻辑正确，故T。
- F；句意：三根铅笔与两块橡皮价值相同；四块橡皮与一把
尺子价格相同。因此，铅笔比尺子贵。利用橡皮做中间媒介，算出尺子单价比铅笔贵，故F。
- F；句意：A班比B班的出勤率高。C班比B班的出勤率低。
因此，A班比C班出勤率低。利用B班做中间媒介，得知A班比C班出勤率高，故F。
- T；句意：果篮中苹果比柠檬多。果篮中柠檬比橘子多。
因此，果篮中苹果比橘子多。逻辑正确，故T。
- F；句意：乘火车出城比乘公共汽车要快。乘公共汽车出
城要比开车慢。因此，乘火车比开车快。以公共汽车为中间媒介，火车和开车都比他快，但二者无法比较，故F。
- F；句意：zoe的花园中，所有的郁金香都是白色的。所有的玫
瑰都是黄色的。因此，所有的花儿不是白色就是黄色。花园中不知有郁金香和玫瑰，因此那两种颜色不能代表所有，故F。
解析
1. 整数包括奇数和偶数，奇数和偶数是并列关系，因此所有奇数都是整数，但不是偶数。
2. 所有舞者都很瘦，所有歌手都是舞者，因此所有歌手都很瘦。
3. 牙签有用，有用的东西是有价值的，因此牙签是有价值的。
4. 三根铅笔与两块橡皮价值相同，四块橡皮与一把尺子价格相同，因此铅笔比尺子贵。
5. A班比B班的出勤率高，C班比B班的出勤率低，因此A班比C班出勤率低。
6. 果篮中苹果比柠檬多，果篮中柠檬比橘子多，因此果篮中苹果比橘子多。
7. 乘火车出城比乘公共汽车要快，乘公共汽车出城要比开车慢，因此乘火车比开车快。
8. zoe的花园中，所有的郁金香都是白色的，所有的玫瑰都是黄色的，因此所有的花儿不是白色就是黄色。
步骤 2：判断每个陈述的结论是否正确
1. 结论错误，因为奇数和偶数是并列关系，不是包含关系。
2. 结论正确，因为所有舞者都很瘦，所有歌手都是舞者，因此所有歌手都很瘦。
3. 结论正确，因为牙签有用，有用的东西是有价值的，因此牙签是有价值的。
4. 结论错误，因为尺子单价比铅笔贵。
5. 结论错误，因为A班比C班出勤率高。
6. 结论正确，因为苹果比橘子多。
7. 结论错误，因为火车和开车都比公共汽车快，但二者无法比较。
8. 结论错误，因为花园中不知有郁金香和玫瑰，因此那两种颜色不能代表所有。