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()一直以来都在CD上汲取养分，从最早真正触G，到现在14号就要考的试。但还未为CD做过什么巨大的贡献。 一直在做GWD31套的题，发现数学有些地方还是很有争议的，有些题目图形也是存在些显示的问题。参考了CD上NN的一些点评，更多的是个人观点，现将有问题的数学题目罗列如下： （注：有的可能是答案真的出了错，有的可能只是自己知识面太狭窄，犯了错，所以敬请希望高手能及时指正，以便大家共同学习） GWD19 Q10: If $1,000 will be deposited in a bank account and I is the dollar amount of interest earned from the original deposit, represented as I = 1000 {(1 + r/100)n – 1}, and the annual interest rate is r percent, is r > 8 percent? (1) The deposit earns a total of $210 in interest in the first 2 years. (2) (1 + r/100)2 > 1.15 A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient. B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient. C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. D. EACH statement ALONE is sufficient. E. Statements (1) and (2) TOGETHER are NOT sufficient. Answer: A D 答案给的是D。自己做时选的是A，因为怕是自己的失误就上CD查询，结果发现大家讨论都是A。所以才坚定了自己的信念。这道题的条件2算出来的结果大约是R>7.**，这个正好处于8以内，所以会以8为界产生两个不同的“区域”，条件2不行。此题答案应该为A。 GWD23 Q30: There are 8 books on a shelf, of which 2 are paperbacks and 6 are hardbacks. How many possible selections of 4 books from this self include at least one paperback? A. 40 B. 45 C. 50 D. 55 E. 60 Answer: D 网上讨论这道题很多，很多人都怀疑答案有错，鉴于这种情况，也坚定了我的信念—答案不该是C而是D。 GWD24 4 A shipment of 8 television sets contains 2 black-and-white sets and 6color sets. If 2 television sets are to be chosen at random from this shipment, what is the probability that at least 1 of the 2 sets chosen will be a black-and-white set? - 1/7 B. ¼ C. 5/14 D. 11/28 E. 13/26(28?)
Answer: E 如红色标记的，E选项的26应该改成28才对。 9 The operation* represents either addition, subtraction, or multiplication of integers, what is the value of 1*0? (1) 0*2=2 (2) 2*0=2
l Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient l Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient l BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. l EACH statement ALONE is sufficient l Statements (1) and (2) TOGETHER are NOT sufficient Answer: D A 答案给的是A。自己做的是选的D，同样发现大家也在CD上争论这道题。我个人觉得虽然条件2可以是加法也可以是减法，但其带来的效果都一样，都是让所求的式子的值为一个固定的1，所以两个条件都可以。 11 An equilateral triangle that has an area of 9 3^1/2 is inscribed in a circle. What is the area of the circle? A . 6pi B. 9pi C. 12 pi D. 9pi 3^1/2 E. 18pi 3^1/2 Answer: C 自己当时做这道题时看不太懂那里的数字的意思，后来觉得应该是9*3^(1/2)，算是提醒下吧，把这道题也粘上了。 16 From May 1 to May 30 in the same year, the balance in a checking account increased. What was the balance in the checking account on May 30? (1) If, during this period of time, the increase in the balance in the checking account had been 12 percent, then the balance in the account on May 30 would have been $504 (2) During this period of time, the increase in the balance in the checking account was 8 percent.
l Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient l Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient l BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. l EACH statement ALONE is sufficient l Statements (1) and (2) TOGETHER are NOT sufficient Answer: C A 答案给的是A。但自己做的是C。因为如果单纯靠A条件，即使知道了月初的数额，在没有知晓百分比的情况下也是计算不出的。所以答案该为C。 18 The annual interest rate earned by an investment increased by 10 percent from last year to this year. If the annual interest rate earned by the investment this year was 1 percent, what was the annual interest rate last year? A. 1% B. 1.1% C. 9.1% D. 10% E. 10.8% Answer: A D 答案给的是D。但很明显的应该是A。 26 Does the decimal equivalent of P/Q, where P and Q are positive integers, contain only a finite number of nonzero digits? (1) P>Q (2) Q=8
l Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient l Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient l BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. l EACH statement ALONE is sufficient l Statements (1) and (2) TOGETHER are NOT sufficient Answer: B E 答案给的是E。但同样，按NN们的讨论，加上自己的个人观点，B是可以满足的。 28 If k=-1, which of the following is (are) true? - k^k=k 2. | k| =-k. 3.k^0=-k
A. 1 only B. 1 and 2 only C. 1 and 3 only D. 2 and 3 only E. 1. 2. and 3. Answer: E 这道题可能会产生误解，是因为3后面那个负号有时显示时会连到等号上，让人看不清楚，拿出来做个提醒。 GWD25 Q10 The sides of a square region, measured to the nearest centimeter, are 6 centimeters long. The least possible value of the actual area of the square region is A.36.00 sq cm B.35.00 sq cm C.33.75 sq cm D.30.25 sq cm E.25.00 sq cm Answer D C 答案给的是C。明眼人都可以看出，这道题是在考察近似计算的问题，要取最小，就应该是边长为5.5了，平方后得到D而不是C。 Q13 If the average (arithmetic mean) of the assessed values of x houses is $212,000 and the average of the assessed values of y other houses is $194,000, what is the average of the assessed values of the x+y houses? (1) x+y=36 (2) x=2y A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient. B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient. C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. D. EACH statement ALONE is sufficient. E. Statements (1) and (2) TOGETHER are NOT sufficient. Answer B C 答案给的是C。实际上知道条件2就足够，根据条件2，在计算时可以通过分子分母间的约分，把唯一的变量Y约除。 Q21 在这里不列题目了。这道题的问题就在于它给的图实在让人无法看懂，做过的人应该知道。 Q23. At a fruit stand yesterday, the price of each apple was $0.10 more than the price of each orange. What was the total revenue from the sale of oranges at the fruit stand yesterday? (1) The number of oranges sold at the fruit stand yesterday was 5 more than the number of apples. (2) The total revenue from the sale of apples at the fruit stand yesterday was $15.00 Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient l Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient l BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. l EACH statement ALONE is sufficient l Statements (1) and (2) TOGETHER are NOT sufficient Answer E C 答案给的是C。但也很明显，这道题能列出的方程个数小于未知数的个数，是无法解出的，选E。 Q27. If M is a positive integer, then M^3 has how many digits? (1) M has 3 digits. (2) M^2 has 5 digits _______________________________________________________________- Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient l Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient l BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. l EACH statement ALONE is sufficient l Statements (1) and (2) TOGETHER are NOT sufficient Answer C E 答案给的是E。上了CD看了NN的解释，她是从M^2可以取10000或者99999这两个极端去分析的；而我是从M入手，对其取100或999，则得到了不同的结果。目前未果，看各位高手来分析下了。 Q31. B C
A D In the figure, each side of square ABCD has length 1, the length of line Segment CE is 1, and the length of line segment BE is equal to the length Of line segment DE. What is the area of the triangular region BCE? a. 1/3 b. (2^-2 )/4 c. 1/2 d. (2^-2)/2 e. 3/4 之前的重题。答案里没有正确的，应该是我写的答案。可以参照之前几套的题目。 Q32. Last year in a group of 30 businesses, 21 reported a net profit and 15 had investments in foreign markets. How many of the businesses did not report a net profit nor invest in foreign markets last year? (1) last year 12 of the 30 businesses reported a net profit and had invest- ments in foreign markets. (2) last year 24 of the 30 businesses reported a net profit or invested in foreign markets, or both. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient l Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient l BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. l EACH statement ALONE is sufficient l Statements (1) and (2) TOGETHER are NOT sufficient Answer D B 答案给的是B。但也是如NN们讨论的一样，这道题的条件1也可以解出的。  
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