GRE-91及答案解析.doc

1、GRE-91及答案解析(总分：25.00，做题时间：90 分钟)一、SECTION 1(总题数：23，分数：25.00)1.What is the average of four consecutive odd numbers starting with 2n+1?A. 4 B. 2n+3 C. 2n+4D. 2n+5 E. n+4（分数：1.00）A.B.C.D.E.2.u v=(v-u)u(u-v)v（分数：1.00）A.B.C.D.（分数：2.00）(1).In which season did Jagr earn the most money per game?A. 1994-1995

2、 B. 1995-1996C. 1996-1997 D. 1997-1998E. 1998-1999（分数：1.00）A.B.C.D.E.(2).In which season did Jagr average the most points per game?A. 1990-1991 B. 1995-1996C. 1996-1997 D. 1997-1998E. 1998-1999（分数：1.00）A.B.C.D.E.3.C. Line k passes through the points (a,b. and (r, s), where (a-r)(b-s)0.（分数：1.00）4.In

3、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?（分数：1.00）填空项 1:_5.The advertised rate for roaming charges is 0. 002 cents per second. What is that in dollars per hour?A. 7.2

4、 B. 2 C. 0.72D. 0.2 E. 0.072（分数：1.00）A.B.C.D.E.（分数：2.00）(1).If the average vehicle occupancy rate for commuters to County X were to increase to 2.8, what would be the approximate percent increase in the occupancy rate?A. 46% B. 54% C. 87%D. 115% E. 215%（分数：1.00）A.B.C.D.E.(2).If the total number of c

5、ommuters to County W is twice the number to County Z, and if the average number of vehicles that transport commuters daily to County W is 30,000, what is the approximate average number of vehicles that transport commuters daily to County Z?A. 12,000 B. 15,000 C. 18,000D. 27,000 E. 36,000（分数：1.00）A.B

6、C.D.E.6. （分数：1.00）A.B.C.D.7.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?（分数：1.00）填空项 1:_8.D

7、 14.8 E. 15.3（分数：1.00）9. （分数：1.00）A.B.C.D.10.63% of a is 72（分数：1.00）A.B.C.D.11.A jar contains two red and two green marbles（分数：1.00）A.B.C.D.12. （分数：1.00）A.B.C.D.13. （分数：1.00）A.B.C.D.14.D. 5 E. 6（分数：1.00）15.A cylinder of gas has height 48 inches, and the base has radius 2 feet（分数：1.00）A.B.C.D.16.The

8、 company at which Mark is employed has 80 employees, each of whom has a different salary. Marks salary of $43,700 is the second-highest salary in the first quartile of the 80 salaries. If the company were to hire 8 new employees at salaries that are less than the lowest of the 80 salaries, what woul

9、d Marks salary be with respect to the quartiles of the 88 salaries at the company, assuming no other changes in the salaries?A. The fourth-highest salary in the first quartileB. The highest salary in the first quartileC. The second-lowest salary in the second quartileD. The third-lowest salary in th

10、e second quartileE. The fifth-lowest salary in the second quartile（分数：1.00）A.B.C.D.E.17.The USS Mathematica sailed 6 knots north, then 5 knots east, then 2 knots south. How far, in knots, was the ship from her starting point?(A) 3 (B) （分数：1.00）A.B.C.D.E.18.For the line with equation y=ax+b, ab0, the

11、 x-intercept is twice the y-intercept.（分数：1.00）A.B.C.D.19.All three circles shown have radius 1 and are tangent to each other. Find the perimeter of the shaded region.A. 3 B. C. （分数：1.00）A.B.C.D.E.20.The fabric needed to make 3 curtains sells for $8. 00 per yard and can be purchased only by the full

12、 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. $24.00D. $16.00 E. $12.80（分数：1.00）A.B.C.D.E.21.In 2000 Paul was twice

13、 as old as his brother Biko. In 2008 Pau I was only four years older than his brother. In what year was Biko born?A. 1990 B. 1992 C. 1996D. 1998 E. 2000（分数：1.00）A.B.C.D.E.GRE-91答案解析(总分：25.00，做题时间：90 分钟)一、SECTION 1(总题数：23，分数：25.00)1.What is the average of four consecutive odd numbers starting with 2n

14、1?A. 4 B. 2n+3 C. 2n+4D. 2n+5 E. n+4（分数：1.00）A.B.C. D.E.解析：2.u v=(v-u)u(u-v)v（分数：1.00）A.B.C. D.解析：（分数：2.00）(1).In which season did Jagr earn the most money per game?A. 1994-1995 B. 1995-1996C. 1996-1997 D. 1997-1998E. 1998-1999（分数：1.00）A.B.C.D. E.解析：(2).In which season did Jagr average the most poi

15、nts per game?A. 1990-1991 B. 1995-1996C. 1996-1997 D. 1997-1998E. 1998-1999（分数：1.00）A.B. C.D.E.解析：3.C. Line k passes through the points (a,b. and (r, s), where (a-r)(b-s)0.（分数：1.00）解析：4.In a graduating class of 236 students, 142 took algebra and 121 took chemistry. What is the greatest possible numb

16、er of students that could have taken both algebra and chemistry?（分数：1.00）填空项 1:_ （正确答案：121）解析：5.The advertised rate for roaming charges is 0. 002 cents per second. What is that in dollars per hour?A. 7.2 B. 2 C. 0.72D. 0.2 E. 0.072（分数：1.00）A.B.C.D.E. 解析：（分数：2.00）(1).If the average vehicle occupancy

17、rate for commuters to County X were to increase to 2.8, what would be the approximate percent increase in the occupancy rate?A. 46% B. 54% C. 87%D. 115% E. 215%（分数：1.00）A.B.C.D. E.解析：(2).If the total number of commuters to County W is twice the number to County Z, and if the average number of vehicl

18、es that transport commuters daily to County W is 30,000, what is the approximate average number of vehicles that transport commuters daily to County Z?A. 12,000 B. 15,000 C. 18,000D. 27,000 E. 36,000（分数：1.00）A. B.C.D.E.解析：6. （分数：1.00）A.B. C.D.解析：7.In the xy-plane, the point with coordinates (-6, -7)

19、 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?（分数：1.00）填空项 1:_ （正确答案：13）解析：8.D. 14.8 E. 15.3（分数：1.00）解析：9. （分数：1.00）A. B.C.D.解析：10.63% of a is 72（

20、分数：1.00）A.B. C.D.解析：11.A jar contains two red and two green marbles（分数：1.00）A.B.C. D.解析：12. （分数：1.00）A.B. C.D.解析：13. （分数：1.00）A. B.C.D.解析：14.D. 5 E. 6（分数：1.00）解析：15.A cylinder of gas has height 48 inches, and the base has radius 2 feet（分数：1.00）A.B. C.D.解析：16.The company at which Mark is employed has

21、 80 employees, each of whom has a different salary. Marks salary of $43,700 is the second-highest salary in the first quartile of the 80 salaries. If the company were to hire 8 new employees at salaries that are less than the lowest of the 80 salaries, what would Marks salary be with respect to the

22、quartiles of the 88 salaries at the company, assuming no other changes in the salaries?A. The fourth-highest salary in the first quartileB. The highest salary in the first quartileC. The second-lowest salary in the second quartileD. The third-lowest salary in the second quartileE. The fifth-lowest s

23、alary in the second quartile（分数：1.00）A.B.C.D.E. 解析：17.The USS Mathematica sailed 6 knots north, then 5 knots east, then 2 knots south. How far, in knots, was the ship from her starting point?(A) 3 (B) （分数：1.00）A.B. C.D.E.解析：18.For the line with equation y=ax+b, ab0, the x-intercept is twice the y-in

24、tercept.（分数：1.00）A.B. C.D.解析：19.All three circles shown have radius 1 and are tangent to each other. Find the perimeter of the shaded region.A. 3 B. C. （分数：1.00）A.B. C.D.E.解析：20.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 o

25、f 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. $24.00D. $16.00 E. $12.80（分数：1.00）A. B.C.D.E.解析：21.In 2000 Paul was twice as old as his brother Biko. In 2008 Pau I was only four years older than his brother. In what year was Biko born?A. 1990 B. 1992 C. 1996D. 1998 E. 2000（分数：1.00）A.B.C. D.E.解析：