GMAT数学例题2

GMAT数学例题2
1. In a certain game played with red chips
and blue chips, each red chip has a point value of X and each blue chip has a point value of Y, where X>Y and X and Y are positive integers. If a player has 5 red chips and 3 blue chips, what is the average (arithmetic mean) point value of the 8 chips that the player has?
(1) The average point value of one red chip and one blue chip is 5.
(2) The average point value of the 8 chips that the player has is an integer.
2. Is n an integer? (1)2
n is an integer.
(2)
is an integer
3. Which number can not be the sum of two
prime numbers?
A. 21
B. 14
C. 18
D. 28
E. 23
4. If 3
2
257r =?? and 2
2
235s =??,
which of the following is equal to the greatest common divisor of r and s? A.25? B.2
25? C.3
2
25?
D. 2357
E. 322
2357
5. If a and b are positive integers, what
is the value of a b +? (1)
58
a b = (2) The greatest common divisor of a and
b is 1.
6. When the integer n is divided by 6, the
remainder is 3. Which of the following is NOT a multiple of 6?
A. n-3
B. n+3
C. 2n
D. 3n
E. 4n
7. There are between 100 and 110 cards in a
collection of cards. If they are counted
out 3 at tie, there are 2 left over, but if they counted out 4 at a time, there is 1 left over. How many cards are in the collection?
A. 101
B. 103
C. 106
D. 107
E. 109
8. How many positive integers k are there
such that 100k is a factor of
()()()2
3
235?
A. None
B. One
C. Two
D. Three
E. Four
9. If n is a positive integer and 23n
k +=.
Which of the following could NOT be a value of K?
A. 1
B. 4
C. 7
D. 25
E. 79
10. What
is
the
units
digit
of
423(13)(17)(29)?
A. 9
B. 7
C. 5
D. 3
E. 1
11. If 1
decimal representation of d equal to 9? (1) d+0.01<2 (2) d+0.05>2
12. If a 3-digit integer is selected at random
from the integers 100 through 199, inclusive, what is the probability that the first digit and the last digit of the integer are each equal to one more than the middle digit? A.
2225 B. 1111 C. 1110 D. 1100 E. 150
13. If n is a positive integer and
5.110n k =?, what is the value of k?
(1) 6000
9
2.60110k =?
14. If P and R are positive, is 25 percent of P
equal to 10 percent of R?
(1) R is 150 percent greater than P
(2) P is 60 percent less than R.
15. A clerk’s salary is $320.00 after a 25%
raise. Before the clerk’s raise, the
supervisor’s salary was 50% greater than
the clerk’s salary. If the supervisor also
receives a raise in the same amount as the
clerk’s raise, what is the supervisor’s
salary after the raise?
A.$370
B.$424
C.$448
D.$480
E.$576
16.Among registered voters in a certain
district, the ratio of men to women is 3:5.
Of the district currently includes 24,000
registered voters, how many additional
men must register to make the ratio 4:5?
A.2000
B.3000
C.4000
D.5000
E. 6000
17.In Township K, 1/5 of the housing units
are equipped with cable television. If
1/10 of the housing units, including 1/3
of those that are equipped with cable
television, are equipped with
videocassette recorders, what fraction of
the housing units have neither cable
television nor videocassette recorders? A.23/30 B.11/15 C.7/10 D.1/6 E.2/15 18.If X and Y are sets of integers, X Y
denotes the set of integers that belong to
set X or set Y, but not both. If X consists
of 10 integers, Y consists of 18 integers,
and 6 of the integers are in both X and Y,
then X Y
consists of how many integers
A. 6
B. 16
C. 22
D. 30
E. 174
19.Which of the following procedures is
always equivalent to adding 5 given
numbers and then dividing the sum by 5?
(1)Multiplying the 5 numbers and then finding the 5th root of the product.
(2)Adding the 5 numbers, doubling the sum, and then moving the decimal point one place to the left
(3)Ordering the 5 numbers numerically and then selecting the middle number
A.None
B. (1) only
C. (2)only
D. (3)only
E. (1) and (3)
20.For the positive numbers, n, n+1, n+2, n+4 and n+8, the mean is how much greater than the median?
A. 0
B. 1
C. n+1
D. n+2
E. n+3
21. A total of 20 amounts are entered on a spreadsheet that has 5 rows and 4 columns; each of the 20 positions in the spreadsheet contains one amount. The average (arithmetic mean) of the amounts in row i is R i(1 ≤ i ≤ 5). The average of the amounts in column j is C j(1 ≤ j ≤ 4). What is the average of all 20 amounts on the spreadsheet?
(1) R1 + R2 + R3 + R4 + R5 = 550
(2) C1 + C2 + C3 + C4 = 440
22.In a meeting of 3 representatives from each of 6 different companies, each person shook hands with every person not from his or her own company. If the
representatives did not shake hands with people from their own company, how many handshakes took place?
A. 45
B. 135
C. 144
D. 270
E. 288
23.How many three-digit numerals begin with a digit that represents a prime number and end with a digit that represents a prime number?
A. 16
B. 80
C. 160
D. 180
E. 240
24.What is the probability that events A and
B both occur?
(1)The probability that event A occurs is 0.8
(2)The probability that event B occurs is 0.6。