海翔GMAT数学课程(陈文彬).doc

此讲义为海翔陈文彬老师的视频课程讲义具体课程地址：/xyzq_3.htm Q1:A certain roller coaster has 3 cars, and a passenger is equally likely to ride in any 1 of the 3 cars each time that passenger rides the roller coaster. If a certain passenger is to ride the roller coaster 3 times, what is the probability that the passenger will ride in each of the 3 cars?A. 0B. 1/9C. 2/9D. 1/3E. 1Answer: -Q2:In 1997 there were 300 female employees at Company C. If the number of female employees at Company C increased by 60 percent from 1977 to 1987, by what percent did the number of female employees at Company C increase from 1987 to 1997?(1)From 1977 to 1997 the number of female employees increased by 200 percent at Company C.(2) In 1977 there were 100 female employees at Company C.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: -Q3:A gardener is going to plant 2 red rosebushes and 2 white rosebushes. If the gardener is to select each of the bushes at random, one at a time, and plant them in a row, what is the probability that the 2 rosebushes in the middle of the row will be the red rosebushes?A. 1/12B. 1/6C. 1/5D. 1/3E. 1/2Answer: -Q4:If 1050 74 is written as an integer in base 10 notation, what is the sum of the digits in that integer?A. 424B. 433C. 440D. 449E. 467Answer: -Q5:If w and c are integers, is w 0?(1) w + c 50(2) c 48A. 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: -Q6:A photographer will arrange 6 people of 6 different heights for photograph by placing them in two rows of three so that each person in the first row is standing in front of someone in the second row. The heights of the people within each row must increase from left to right, and each person in the second row must be taller than the person standing in front of him or her. How many such arrangements of the 6 people are possible?A. 5B. 6C. 9D. 24E. 36Answer: -Q7:Running at their respective constant rates, machine X takes 2 days longer to produce w widgets than machine Y. At these rates, if the two machines together produce 5/4 w widgets in 3 days, how many days would it take machine X alone to produce 2w widgets?A. 4B. 6C. 8D. 10E. 12Answer: -Q8:Joanna bought only $0.15 stamps and $0.29 stamps. How many $0.15 stamps did she buy?(1) She bought $4.40 worth of stamps.(2) She bought an equal number of $0.15 stamps and $0.29 stamps.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: -Q9:A positive integer n is said to be “prime-saturated” if the product of all the different positive prime factors of n is less than the square root of n. What is the greatest two-digit prime-saturated integer?A. 99B. 98C. 97D. 96E. 95Answer: -Q10:For a convention, a hotel charges a daily room rate of $120 for 1 person and x dollars for each additional person. What is the charge for each additional person?(1) The daily cost per person for 4 people sharing the cost of a room equally is $45.(2)The daily cost per person for 2 people sharing the cost of a room equally is $25 more than the corresponding cost for 4 people.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: -Q11:What is the median number of employees assigned per project for the projects at Company Z?(1)25 percent of the projects at Company Z have 4 or more employees assigned to each project.(2) 35 percent of the projects at Company Z have 2 or fewer employees assigned to each project.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: -Q12:A jar contains 16 marbles, of which 4 are red, 3 are blue, and the rest are yellow. If 2 marbles are to be selected at random from the jar, one at a time without being replaced, what is the probability that the first marble selected will be red and the second marble selected will be blue?A. 3/64B. 1/20C. 1/16D. 1/12E. 1/8Answer: -Q13: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. 96B. 75C. 48D. 25E. 12Answer: -Q14: 20 ftThe figure above shows the dimensions of a semicircular cross section of a one-way tunnel. The single traffic lane is 12 feet wide and is equidistant from the sides of the tunnel. If vehicles must clear the top of the tunnel by at least foot when they are inside the traffic lane, what should be the limit on the height of vehicles that are allowed to use the tunnel?A. 5 ftB. 7 ftC. 8 ft D. 9 ftE. 10 ftAnswer: -Q15: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 xA.I onlyB.II onlyC.III onlyD.I and IIE.II and III Answer: -Q16:If a and b are positive, is (a-1 + b-1)-1 less than (a-1b-1)-1?(1) a = 2b(2) a + b 1A. 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: -Q17:On a certain transatlantic crossing, 20 percent of a ships passengers held round-trip tickets and also took their cars abroad the ship. If 60 percent of the passengers with round-trip tickets did not take their cars abroad the ship, what percent of the ships passengers held round-trip tickets?A. 33 1/3%B. 40%C. 50%D. 60%E. 66 2/3%Answer: -Q18:A construction company was paid a total of $500,000 for a construction project. The companys only costs for the project were for labor and materials. Was the companys profit for the project greater than $150,000?(1) The companys total cost was three times its cost for materials.(2) The companys profit was greater than its cost for labor.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: -Q19: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. 40B. 45C. 50D. 55E. 60Answer: Q20: E B C ADIn 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. 1/3B. (2)/4C. 1/2D. (2)/2E. 3/4Answer: -Q21:There are 8 magazines lying on a table; 4 are fashion magazines and the other 4 are sports magazines. If 3 magazines are to be selected at random from the 8 magazines, what is the probability that at least one of the fashion magazines will be selected?A. 1/2B. 2/3C. 32/35D. 11/12E. 13/14Answer: -Q22:What is the remainder when the two digit, positive integer x is divided by 3?(1) The sum of the digits of x is 5.(2) The remainder when x is divided by 9 is 5.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: -Q23:If (y+3)(y-1) (y-2)(y-1) = r(y-1), what is the value of y?(1) r2 = 25(2) r = 5A. 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: -Q24:If n and k are positive integers, is n/k an even integer?(1) n is divisible by 8.(2) k is divisible by 4.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: -Q25:If n is a positive integer and r is the remainder when (n-1)(n+1) is divided by 24, what is the value of r?(1) 2 is not a factor of n.(2) 3 is not a factor of n.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: -Q26:Which of the following is equal to 1/(3 - 2)2?A. 1B. 5C. 6D. 5 - 6E. 5 + 26Answer: -Q27:If S is a set of ten consecutive integers, is the integer 5 in S?(1) The integer 3 is in S.(2) The integer 4 is in S.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: -Q28:If Line k in the xy-plane has equation y = mx + b, where m and b are constants, what is the slope of k?(1) k is parallel to the line with equation y = (1-m)x + b +1.(2) k intersects the line with equation y = 2x + 3 at the point (2, 7).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: -Q29:If M is the least common multiple of 90, 196, and 300, which of the following is NOT a factor of M?A. 600B. 700C. 900D. 2,100E. 4,900Answer: -Q30:What is the ratio of the average (arithmetic mean) height of students in class X to the average height of students in class Y?(1) The average height of the students in class X is 120 centimeters.(2)The average height of the students in class X and class Y combined is 126 centimeters.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: -Q31:On Saturday morning, Malachi will begin a camping vacation and he will return home at the end of the first day on which it rains. If on the first three days of the vacation the probability of rain on each day is 0.2, what is the probability that Malachi will return home at the end of the day on the following Monday?A. 0.008B. 0.128C. 0.488D. 0.512E. 0.640Answer: -Q32If x 0.9, which of the following could be the value of x?A. 0.81B.