Re: [計量] 好多題計量請教

看板GRE (GRE入學考試)作者denru01 (阿儒)時間15年前 (2011/01/15 22:25)推噓1(1推 0噓 2→)

留言3則, 1人參與討論串10/26 (看更多)

※ 引述《balance9235 (退伍變米蟲)》之銘言： : 1. A rectangular solid has a volume of 30, and its edges have integer lengths. : What is the greatest possible surface area of this solid? : (A) 82 : (B) 86 : (C) 94 : (D) 122 : (E) 180 ANS:(D) 我算1.3.10表面積94 1.1.30 => (1+30+30)*2 = 122 : 2. Which of the following is the second power of sqrt(1+√1) : (A) 1 : (B) √2 : (C) 2 : (D) 4 : (E) 1+√2 ANS:(C) 我算1+√1 2 = 1+√1不是嗎？ : 3. In the xy-plane, line l passes through the origin and is perpendicular to : the line 4x + y = k, where k is a constant. If the two lines intersect at : the same point (t, t+1), what is the value of t? : (A) 4/3 : (B) 5/4 : (C) 3/4 : (D) -5/4 : (E) -4/3 ANS:(E) y = k - 4x => 斜率-4。垂直 => m*-4 = -1 => m = 1/4 => y = 1/4x t+1 = 1/4*t => t = -4/3 : 4. A bag contains red gloves, black gloves, ans white ones. What is the LEAST : number of gloves that must be taken out of the bag to be sure of having : 4 pairs of gloves? : (A) 6 : (B) 8 : (C) 9 : (D) 10 : (E) 12 ANS:(D) 原本有幾雙也不知道.... 最慘情況4雙+2單隻 => 10隻 : 5. Each of the following numbers has one digit blotted out. Which of the : numbers CANNOT be a sum of two consecutive odd integers? : (A) 2,□24 : (B) 3,□32 : (C) 4,□44 : (D) 5,□54 : (E) 6,□68 ANS:(D) 不知道怎麼判斷兩連續奇數和 => x+x+2 = 2x+2 (且x為奇數) 看哪個減2再除2後不是奇數 : 6. If p, q, r represent different positive integers, and pqr = 2009, what is : the greatest result of p + q + r? : (A) 49 : (B) 55 : (C) 91 : (D) 295 : (E) 2011 ANS:(D) 2009 = 7*7*41 => 1+7+7*41 = 295 : 7. If two cards are drawn drom a deck without replacement, the probability : that both are aces is : (A) 1/26 : (B) 7/52 : (C) 16/2652 : (D) 12/2652 : (E) 12/103 ANS:(D) 我的式子列 (C4取2*C13取1)/C52取2 4/52 * 3/51 = 12/2652 : 8. In the xy-plane, the coordinates of △ABC are (0,0), (4,1) and (2,4), : respectively. What is the area of △ABC? : (A) 4 : (B) 5 : (C) 6 : (D) 7 : (E) 8 ANS:(D) 邊長有根號不知道怎麼用三邊長求面積列行列式 |0 0 1| |4 1 1| * 1/2 = 7 |2 4 1| : 9. In the xy-plane, O is the center of circle with coordinate (m,4), and a : point (m,-1) is on the circle. : Column A Column B : The circumference 32 : of circle O. ANS:B (x-m)^2 + (y-4)^2 = r^2 => (m,-1)代入 (m-m)^2 + (-1-4)^2 = r^2 => r = 5 周長 = 2*pi*r = 10pi < 32 : 10. At the corporate headquarters of a large enterprise, outside each office : there is a keyboard, on which there are two letters, A and B, and digits : from 0 to 9, inclusive. To gain entrance to an office, an employee must : punch in an access code. If a code consists of the letter A or B followed : by either 2 or 3 different digits, how many different access codes are : there? : (A) 2,200 : (B) 2,000 : (C) 1,620 : (D) 1,560 : (E) 1,440 ANS:(C) C2取1*C10取2 + C2取1*C10取3不對 2 different digits: 10*9 = 90 3 different digits: 10*9*8 = 720 A or B: 2*(90+720) = 1620 : 今天題目比較少，一樣要麻煩大家了！ -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.112.218.68