※ 引述《PINKENVI (勿忘初衷)》之铭言： : Q16: : If k is a positive integer, what is the remainder when 2^k is divided by 10 ? : (1) k is divisible by 10. : (2) k is divisible by 4. : Answer: B : 这题我不太知道怎麽算! (1) 10的因数为2跟5，k是十的奇数倍时余数为4，是偶数倍时为6，无法确定。 (2) 4的因数为2，k不管是4的奇数或偶数倍，余数都必为6。 : Q25: : Of the high school students who participated in a recent survey, : 110 had taken a course in biology and 230 had taken a course in history. : How many students participated in the survey? : (1)Of the students who participated in the survey, 120 had taken neither a course in biology nor a course in history. : (2)Of the students who participated in the survey, 60 had taken both a course in biology and a course in history. : Answer:C : 这题为啥是C阿!如果已经个别知道biology和history的人数!又只要知道他们重复的人数! : 那不就是用P(AUB)=P(A)+P(B)-P(A交集B)就可算出嘛? : 我不懂为啥还要用到(1)? : 嗯 谢谢回答! :) 因为不是给你机率，是给你实际人数。 第一题你稍微算一下就知道 第二题你是被混淆了^^ 应该是这样没错吧^^ --

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