※ 引述《PINKENVI (勿忘初衷)》之銘言： : 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 : 這題我不太知道怎麼算! (1) 10的因數為2跟5，k是十的奇數倍時餘數為4，是偶數倍時為6，無法確定。 (2) 4的因數為2，k不管是4的奇數或偶數倍，餘數都必為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 : 這題為啥是C阿!如果已經個別知道biology和history的人數!又只要知道他們重複的人數! : 那不就是用P(AUB)=P(A)+P(B)-P(A交集B)就可算出嘛? : 我不懂為啥還要用到(1)? : 嗯 謝謝回答! :) 因為不是給你機率，是給你實際人數。 第一題你稍微算一下就知道 第二題你是被混淆了^^ 應該是這樣沒錯吧^^ --

※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 125.225.155.14 ※ 編輯: windton 來自: 125.225.155.14 (12/17 19:01)