Re: [計量] 3題陳向東+1題機經請教

看板GRE作者answertw (Cy yung)時間14年前 (2010/08/25 11:10)推噓2(2推 0噓 4→)

留言6則, 4人參與討論串3/3 (看更多)

※ 引述《tping (牆壁,眼睛,膝蓋)》之銘言： : 1. T is no more than 20 percent greater than the integer x, : and T is no smaller than a number 20 percent less than the integer x. : If T = 60, which of the following indicates the smallest possible : interval for x? : A. 40=<x=<80 : B. 48=<x=<75 : C. 48=<x=<72 : D. 50=<x=<78 : E. 50=<x=<75 : 答案是E，話說我推出 60*0.8<x<60*1.2 感覺C更小啊... 這題要搞清楚是"誰"的百分之二十 20% greater than x 代表他頂多比x大百分之二十所以是x的1.2倍,並不是T的0.8倍,這種題目常出兩種算法答案不會一樣第二部份是比x小20%,比x小代表x乘以0.8=T並不是T乘以1.2=x : 2. If 55percent of a group of people have brown hair and 80percent of the same : group do not have red hair, what fraction of those who do not have brown hair : have red hair? : A: 4/9 : 3. If the perimeter of a triangle is 18, then the length of one of the sides : CANNOT be : 答案是9，因為兩邊和=第三邊 : 可是我覺得另一個答案1也會造成同樣的情況(1+8=9)所以是題目錯了嗎?? : 4. A tennis game is played between two players. A player wins the game if he : wins three out of the total sets. : colA. probability that the match is decidedin the first three match : colB. 0.15 : 印度網答案給B 因為0.5*0.5*0.5=0.125<0.15 : 可是我覺得1.題目沒有給誰的勝率比較高 : 2.問誰贏，因為機率不同，A的答案也不同 : 請問大家有何看法? 這題不知道剛剛大家討論解決了沒~ 應該是"連三場贏球"/所有可能那就A win + B win = 2 (分子) 3C5 (五取三) X 2 = 20 答案是0.1 < 0.15 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.112.115.226 ※ 編輯: answertw 來自: 140.112.115.226 (08/25 11:22)

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