GRE数学
第一部分 数学基础知识
断点伴奏一、代数Algebra
例1 比较大小：.
The number of distinct positive factors of n 14比较大小
例2：252因子的个数是多少？
例3 比较大小：A printer numbered concutively the pages of a book, beginning with 1 on the first page. In numbering the page, he printed a total of 204 digits.
The number of pages in the book 105
例4 比较大小： In a certain two-digit number,
the units' digit is twice the tens' digit. 5
The tens' digit
例5比较大小：
二、描述统计 descriptive statistics
例6 比较大小：某长方形的周长为40，该长方形的最大面积 100
例7 比较大小：空间5个点能够构成的直线数目 10
例8：求3，13，17的标准方差。
三、排列组合combination、概率 probability
1． 排列组合 排列计算公式： ， 组合计算公式： 。
2． 概率
例9：假如世界杯比赛共有32支球队，分成8个组，每组4个队，每组前两名出线，然后成对进行淘汰赛，直至决赛决出冠军，并且淘汰队不参加比赛，从中间任选出一场比赛观看是半决赛的机会有多大？
例10：有4对男女，每对中有1男1女，从每对中选出1人，选出2男2女的概率是多少？
例11：有3个打字员为4家公司服务，如果4家公司各有1份文件要录入，他们只能找到这3个打字员录入，且各公司对打字员的要求是随机的。问每个打字员都收到文件的概率是多少？
例12：两个骰子，六面的值分别为1，2，3，4，5，6，投掷这两个骰子，问其中一个骰子的值比另一个的值大2的概率为多大?
四、几何(Geometry)
| | 例13 比较大小：R is a point in the rectangular coordinate system and OR=5. The x-coordinate of point R 5 4.9 |
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例14 比较大小： (RS)2+(ST)2 (RT)2 | 例15： According to the graph above, when x=3, y is most nearly: (A) -1 (B) -1/2 (C) 0 (D) 1/2 (E) 1 |
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五、文字题(Word Problem)
1. 利息问题(interest)
单利 simple interest 复利 compound interest
例16： If $ 8000 is invested at 6 percent simple annual interest, how much interest is earned after 3 months?
例17：If $ 10,000 is invested at 10 percent simple annual interest, compound miannually, what is the balance after 1 year?
2. 折扣问题(discount)
例18：The price of an item is discounted by 20 percent and then this reduced price is discounted by an additional 30 percent. The two discounts are equal to an overall discount of what percent?
3. 英美常识问题
GRE难题解析
例1：On a certain number line, if -7 is a distance of 4 from n and 7 is a distance of 18 from n ,then n=?
(A) 25 (B) 11 (C)- 3 (D) 11 (E)-11
例2：The diagram reprents a rectangular garden. The shaded regions are planted in flowers, and the unshaded region is a walk 2 feet wide. All angles are right angles. The sum of the areas of the 2,800 square feet shaded regions | |
例3：The map shows the only roads that connect the four towns and shows the distance along each road. | |
The road distance between Austen and Seburg | | The road distance between Coaltown and Woodland |
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例4：How many positive integers less than 20 are equal to the sum of a positive multiple of 3 and a positive multiple of 4?
(A) Two (B) Five (C) Seven (D) Ten (E) Nineteen
例5：Which of the following symbols should be substituted for to make both of the statements true for all integers n such that -2< n≤3?电脑网络怎么连接 (A) ≤ (B) < (C) = (D) > (E) ≥ | 4-n 6 4-n 5 |
| 白带量多 | 知柏三子汤 |
例6：In a soccer league, If there were 10 teams and each team played each of the other teams 16 times, how many games did each team play?
(A) 144 (B) 140 (C) 134 (D) 125 (E) 106
例7：(NOTE: DRAWN TO SCALE)
POPULATION OF THE U.S. AGE 55 AND OVER 1984 AND PROJECTIONS FOR 1995 | INCOME DISTRIBUTION FOR POPULATION OF THE U.S. AGE 55 AND OVER,1984 |
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In 1984 median income for a person in the 55~64 age category was in which of the following intervals?
(A) less than ＄10,000 (B) ＄10,000~＄19,999 (C) ＄20,000~＄24,999 (D) ＄25,000~＄34,999 (E) ＄35,000~＄49,999
例8：A sample of employees were tasted on data-entry skills for one hour, and the number of errors (x) they made and the percent of employees (p) making x errors were recorded as follows.
excel转wordNumber of error x | 0 | 1 | 2 | 3 | 4 | 5 | 6 or more |
Percent of employees P | 2% | 5% | 10% | 24% | 14% | 20% | 22% |
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what was the median number of errors in the sample?
(A) 3 (B) 3.5 (C) 4 (D) 4.5
(E) It cannot be determined from the information given.
碧根果和核桃有什么区别
例9：d=7.56872 and D is the decimal expression for d rounded to the nearest thousandth.
The number of decimal place where d and D differ | 4 |
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例10：In a certain country, a person is born every 3 conds and a person dies every 10 conds. Therefore, the birth and death rates account for a population growth rate of one person every
例进口猫粮品牌11：Of the positive integers that are multiples of 30 and are less than or equal to 360, what fraction are multiples of 12?
(A) 1/6 (B) 1/5 (C) 1/3 (D) 2/5 (E) 1/2
袜子英语怎么读
例12：The figure shows a large square formed by fitting three L-shaped tiles and one small square tile together. If a rectangular floor 10 feet by 12 feet is to be tiled in large squares of this design, how many L-shaped tiles will be needed?
(A) 810 (B) 405 (C) 270 (D) 135 (E) 45 | 8inches |
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