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标题: 再来一道难题 [打印本页]

作者: ciscogeek 时间: 2008-2-18 22:43
标题: 再来一道难题

During a behavioral experiment in a psychology class, each student is asked to compute his or her lucky number by raising 7 to the power of the student's favorite day of the week(numbered 1 through 7 for Monday through Sunday respectively), multiplying the result by 3, and adding this to the doubled age of the student in years, rounded to the nearest year. If a class consists of 28 students, what is the probability that the median lucky number in the class will be a non-integer?

a. 0%
b.10%
c. 20%
d. 30%
e. 40%

ans. a

谁来解释一下，谢谢了。

作者: heslaw 时间: 2008-2-18 23:06

这道题一点都不难

不论怎么搞

每个学生最后的答案一定是偶数

所以meadian 一定是integer

作者: ciscogeek 时间: 2008-2-19 22:03

惭愧了。

median是中数还没反应过来。

作者: anothermonk 时间: 2008-2-20 12:19
这道题是啥意思看都看不懂的说

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