新GRE数学真题(OG 机经)[精华].pdf

1 y 2x2 7x 3 x y 2 the figure above shows the graph of a function f defined by f x 2x 4 for all numbers x for which of the following functions g defined for all numbers x does the graph of g intersect the graph of f a g x x 2 b g x x 3 c g x 2x 2 d g x 2x 3 e g x 3x 2 3 each employee of a certain company is in either department x or department y and there are more than twice as many employees in department x as in department y the average arithmetic mean salary is 25 000 for the employees in department x and is 35 000 for the employees in department y which of the following amounts could be the average salary for all of the employees in the company indicate all such amounts a 26 000 b 28 000 c 29 000 d 30 000 e 31 000 f 32 000 g 34 000 4 working alone at its constant rate machine a produces k car parts in 10 minutes working alone at its constant rate machine b produces k car parts in 15 minutes how many minutes does it take machines a and b working simultaneously at their respective constant rates to produce k car parts minutes 5 1 if the dollar amount of sales at store p was 800 000 for 2006 what was the dollar amount of sales at that store for 2008 a 727 200 b 792 000 c 800 000 d 880 000 e 968 000 2 at store t the dollar amount of sales for 2007 was what percent of the dollar amount of sales for 2008 give your answer to the nearest 0 1 percent 3 which of the following statements must be true indicate all such statements a for 2008 the dollar amount of sales at store r was greater than that at each of the other four stores b the dollar amount of sales at store s for 2008 was 22 percent less than that for 2006 c the dollar amount of sales at store r for 2008 was more than 17 percent greater than that for 2006 6 a certain store sells two types of pens one type for 2 per pen and the other type for 3 per pen if a customer can spend up to 25 to buy pens at the store and there is no sales tax what is the greatest number of pens the customer can buy a 9 b 10 c 11 d 12 e 20 7 a list of numbers has a mean of 8 and a standard deviation of 2 5 if x is a number in the list that is 2 standard deviations above the mean what is the value of x x 8 frequency distribution for list x number 1 2 3 5 frequency 10 20 18 12 frequency distribution for list y number 6 7 8 9 frequency 24 17 10 9 list x and list y each contain 60 numbers frequency distributions for each list are given above the average arithmetic mean of the numbers in list x is 2 7 and the average of the numbers in list y is 7 1 list z contains 120 numbers the 60 numbers in list x and the 60 numbers in list y quantity a quantity b the average of the 120numbers in list z the median of the 120 numbers in list z 9 the figure above shows the graph of the function f in the xy plane what is the value of f f 1 a 2 b 1 c 0 d 1 e 2 10 by weight liquid a makes up 8 percent of solution r and 18 percent of solution s if 3 grams of solution r are mixed with 7 grams of solution s then liquid a accounts for what percent of the weight of the resulting solution a 10 b 13 c 15 d 19 e 26 11 of the 700 members of a certain organization 120 are lawyers two members of the organization will be selected at random which of the following is closest to the probability that neither of the members selected will be a lawyer a 0 5 b 0 6 c 0 7 d 0 8 e 0 9 12 line k lies in the xy plane the x intercept of line k is 4 and line k passes through the midpoint of the line segment whose endpoints are 2 9 and 2 0 what is the slope of line k give your answer as a fraction 13 in the course of an experiment 95 measurements were recorded and all of the measurements were integers the 95 measurements were then grouped into 7 measurement intervals the graph above shows the frequency distribution of the 95 measurements by measurement interval quantity a quantity b the average arithmetic the median of the 95 mean of the 95 measurements measurements 14 the random variable x is normally distributed the values 650 and 850 are at the 60th and 90th percentiles of the distribution of x respectively quantity a quantity b the value at the 75th 750 percentile of the distribution of x 15 if 1 x x2 x3 60 then the average arithmetic mean of x x2 x3 and x4 is equal to which of the following a 12x b 15x c 20 x d 30 x e 60 x 16 parallelogram opqr lies in the xy plane as shown in the figure above the coordinates of point p are 2 4 and the coordinates of point q are 8 6 what are the coordinates of point r a 3 2 b 3 3 c 4 4 d 5 2 e 6 2 17 let s be the set of all positive integers n such that n2 is a multiple of both 24 and 108 which of the following integers are divisors of every integer n in s indicate all such integers a 12 b 24 c 36 d 72 18 the range of the heights of the female students in a certain class is 13 2 inches and the range of the heights of the male students in the class is 15 4inches which of the following statements individually provide s sufficient additional information to determine the range of the heights of all the students in the class indicate all such statements a the tallest male student in the class is 5 8 inches taller than the tallest female student in the class b the median height of the male students in the class is 1 1 inches greater than the median height of the female students in the class c the average arithmetic mean height of the male students in the class is 4 6 inches greater than the average height of the female students in the class 19 a random variable y is normally distributed with a mean of 200 and a standard deviation of 10 quantity a quantity b the probability of the event 1 6 that the value of y is greater than 220 20 in a graduating class of 236 students 142 took algebra and 121 took chemistry what is the greatest possible number of students that could have taken both algebra and chemistry students 21 the total amount that mary paid for a book was equal to the price of the book plus a sales tax that was 4 percent of the price of the book mary paid for the book with a 10 bill and received the correct change which was less than 3 00 which of the following statements must be true indicate all such statements a the price of the book was less than 9 50 b the price of the book was greater than 6 90 c the sales tax was less than 0 45 22 which of the following statements individually provide s sufficient additional information to determine the area of triangle abc above indicate all such statements a dbc is an equilateral triangle b abd is an isosceles triangle c the length of bc is equal to the length of ad d the length of bc is 10 e the length of ad is 10 23 the fabric needed to make 3 curtains sells for 8 00 per yard and can be purchased only by the full yard if the length of fabric required for each curtain is 1 6 yards and all of the fabric is purchased as a single length what is the total cost of the fabric that needs to be purchased for the 3 curtains a 40 00 b 38 40 c 24 00 d 16 00 e 12 80 24 the fabric needed to make 3 curtains sells for 8 00 per yard and can be purchased only by the full yard if the length of fabric required for each curtain is 1 6 yards and all of the fabric is purchased as a single length what is the total cost of the fabric that needs to be purchased for the 3 curtains a 40 00 b 38 40 c 24 00 d 16 00 e 12 80 25 in the xy plane the point with coordinates 6 7 is the center of circle c the point with coordinates 6 5 lies inside c and the point with coordinates 8 7 lies outside c if m is the radius of c and m is an integer what is the value of m m 26 what is the least positive integer that is not a factor of 25 and is not a prime number a 26 b 28 c 36 d 56 e 58 27if 1 is expressed as a terminating decimal how many nonzero digits 1 211 517 will the decimal have a one b two c four d six e eleven 28 eight hundred insects were weighed and the resulting measurements in milligrams are summarized in the boxplot below a what are the range the three quartiles and the interquartile range of the measurements b if the 80th percentile of the measurements is 130 milligrams about how many measurements are between 126 milligrams and 130 milligrams 29 the figure shows a normal distribution with mean m and standard deviation d including approximate percents of the distribution corresponding to the six regions shown suppose the heights of a population of 3 000 adult penguins are approximately normally distributed with a mean of 65 centimeters and a standard deviation of 5 centimeters a approximately how many of the adult penguins are between 65 centimeters and 75 centimeters tall b if an adult penguin is chosen at random from the population approximately what is the probability that the penguin s height will be less than 60 centimeters give your answer to the nearest 0 05 j4 n j4 n 8 8 5 f9f91 1 3 z w 30 f 3 z 6 xf zlist l f 6 z w j a 2 0 z g 9 z 6 6 f m 0 ld 6m 0 ld m 0 0 z r m 0 6m 0 u f 9 z1 x 0 50 3 zf9n c f x f x f 5 0 e 61 w 4 h a 5 y y r 0 z 8 0 z 8 y a 100 r r 5 1 9 f 9 z f92 z f9 g 3 6 x 0 0 y e w l a 7 q p 70 6 975 85 6 60 r70 85 6 k 6 b 35 8 the average test score of 2 boys is 75 and that of 3 girls is 95 what is the total average score of 5 people 5 f9 jf9 j 1 0 b range 21 rf b 0 0 w l 7 4 8 0 p right 2 73 0 z 6 z j50 6 x a a1 3 4 a2 8 9 3 4 a a5 b 1 2 f9 a a5 7 12 4 5 n k 3 7 column a column b n k k n 1 a line passes 4 6 6 5 column a column b 6 7 8 9 10 the slope of the line a 1 2 u v w z and u v w z are odd consecutive integers column a column b the median of 5 integers the range of 5 integers f x 2x 4y 6 and g x 4x 2y 10 f x and g x intersect at a point a b column a column b a b when 15 is divided by z remainder is 2 column a column b z 3 in the figure above this is regular hexagon column a column b the length of ab the length of cd 11 12 13 14 15 16 9 0 4 lo 600 4 5 6 5 1 6 3 1 w 6 j84 6 7 j5 w 6 w 90 6 jk 0 4 column a column b the sum of a b c 180 0 x 1 column a column b n x n the mean of 600 females is 80 and standard deviation is 5 86 is kth percentile the mean of 400 males is 75 and standard deviation is 3 81 is nth percentile column a column b k n in the figure above the line passes 0 0 4 4 column a column b lal lbl x y 2 column a column b y x 2 1 25y column a column b 5n 3 3 5n 1 2 400 4 5 6 5 1 6 3 1 w 6 j 80 6 7 j3 w 6 w 86 6 jn l k n b1 w a 5 v a f g n 17 p1 3 4 pn 1 1 n 1 2 pn 1 n 2 p8 1 2 w l 0 l 0 1 3 z 76 x 3 0 w rx 0 l a 27 2 n f xb 6 t z 4 lo 0 z h x 0e c z g f 0 z 4 lo zlo f 9 z h f xl 04 f 0e c 0 f j a z h n n 1 a 100 x 7 p j a 3 7 in 1981 ms jones paid 20 percent less in federal taxes than in 1980 and in 1982 she paid 30 percent more in 1981 in 1982 ms jones paid what percent less or more in federal taxes than in 1980 4 abc is right triangle and angle b d are right angles bac 30 ac 4 what is the length of bd 5 y 6 the average of set a consisting 30 integers is 30 if the value of each components of s