Re: [計量] GWD幾題請教

看板GMAT (GMAT入學考試)作者catspace (柏拉圖的永恆...)時間17年前 (2008/09/27 09:49)推噓0(0推 0噓 0→)

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※ 引述《minie (散落在我手中的是溫柔)》之銘言： : GWD-01-Q2 : If 2 different representatives are to be selected at random from a group of : 10 employees and if p is the probability that both representatives selected : will be women, is p > 1/2 ? : (1) More than 1/2 of the 10 employees are women. : (2) The probability that both representatives selected will be men is : less than 1/2 : ANS:E : GWD-01-Q15 : If p is the product of the integers from 1 to 30, inclusive, what is the : greatest integer k for which 3^k is a factor of p? : A.10 : B.12 : C.14 : D.16 : E.18 : 請問有快速的算法嗎 ANS:C : GWD-01-26 : If the units digit of the three-digit positive integer k is nonzero, what is : the tens digit of k? : (1) The tens digit of k + 9 is 3. : (2) The tens digit of k + 4 is 2. : ANS:A : GWD-02-02 : When positive integer x is divided by positive integer y, the remainder is 9. : If x/y = 96.12, what is the value of y? : A.96 : B.75 : C.48 : D.25 : E.12 : ANS:B : GWD-02-08 : The operation $ is defined for all nonzero numbers a and b by a $ b = a/b – : b/a. If x and y are nonzero numbers, which of the following statements must : be true? : I.x $ xy = x(1 $ y) : II.x $ y = -(y $ x) : III.1/x $ 1/y = y $ x : A. I only : B. II only : C. III only : D. I and II : E. II and III : ANS:E : GWD-02-17 : Q17: : If a and b are positive, is (a^-1 + b^-1)-1 less than (a^-1 b^-1)-1? : (1) a = 2b : (2) a + b > 1 : ANS:B : GWD-02-22 : A construction company was paid a total of $500,000 for a construction : project. The company’s only costs for the project were for labor and : materials. Was the company’s profit for the project greater than $150,000? : (1) The company’s total cost was three times its cost for materials. : (2) The company’s profit was greater than its cost for labor. : ANS:C : 以上題目都是想很久想不通的 : 先謝謝各位的幫忙 01-02 C6取2 1 (1) 女性至少6個，P > ------- = --- ......insufficient C10取2 3 (2) 只知道 P(both women) + P(one man & one woman) > 1/2 ......insufficient (1)+(2) 仍然insufficient # ------------------------------------------------------- 01-15 你把1~30裡"3的倍數"列出來，看有幾個3的乘積 3、6、9、12、15、18、21、24、27、30 共有14個3的乘積 Ans: C # ------------------------------------------------------- 01-26 (1) 既然個位數不等於0，則無論是1~9的哪一個，K+9都會進位得知K的十位數一定是2 ......sufficient (2) 考慮116和120兩個數你就明白了 ......insufficient Ans: A # ------------------------------------------------------- 02-02 x/y = 96.12 = 96 + 12/100 = 96 + 3/25 = 96 + 9/75 y = 75 # ------------------------------------------------------- 02-08 I. x $ xy = 1/y - y =\= x(1/y - y) = x(1 $ y) II. x $ y = x/y - y/x = - (y $ x) III. 1/x $ 1/y = y/x - x/y = y $ x 只有 II & III 正確 Ans: E # ------------------------------------------------------- 02-17 假設原式成立，化簡: (1/a + 1/b) -1 < 1/ab - 1 a+b/ab < 1/ab ，since ab>0，then a+b<1 也就是說原式成立條件為 a+b<1 (1) 不得而知 ......insufficient (2) 既然條件說 a+b>1，則可得出"原式不成立"的結論 ......sufficient Ans: B # ------------------------------------------------------- 02-22 若題目成立題目則 L + M < 350000 (1) L + M = 3M ， L = 2M ......insufficient (2) 500000 - ( L + M ) > L ， 2L + M < 500000 ......insufficient (1)+(2) 5M < 500000 ， M < 100000 ，代入(1)則 L < 200000 L + M < 300000 .......sufficient Ans: C # ※ 編輯: catspace 來自: 220.136.225.145 (09/27 17:36)