GMAT数学例题1
1.If the operation is defined
by
x y=
for all positive numbers x and y,then(545)60
=
A.30
B.60
C.90
D.
E.
2. If a b
ad bc
c d
=-for all numbers a, b,
c, and d, then 35 24 -
=
A.-22
B.-2
C.2
D.7
E. 22
3. The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximated what percent of a day?
A.14%
B.16%
C.24%
D.28%
E. 72%
4. If x and y are different prime numbers, each greater than 2, which of the following must be true?
I x+y≠91
II x y
-is an even integer
III x
y
is not an integer
A. II only
B. I and II only
C. I and III only
D. II and III only
E. I, II, III
5. When 20 is divided by the position integer k, the remainder is 2
k-.Which of the following is a positive value of k?
A. 8
B. 9
C. 10
D. 11
E. 12 6. What is Steve’s annual salary and Maria’s annual salary?
(1) The combined total of the annual salaries of Steve and Maria is $80,000
(2) If Steve were to receive a 10 percent increase in annual salary and Maria an 8 percent increase, their combined annual salaries would be $87,000
7. 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.
8. Is m an even integer?
(1)3
m a
=, for some integer a
(2)21
m b
=+,for some integer b.
9. What is the value of x?
(1) 6
x y
-=
(2)5530
x y
-=
10. What is the value of 25
x y
-
(1)8
x y
+=
(2)8208
x y
-=
11. Is x equal to 1?
(1)21
x=
(2)220
x x
--=
12. There are three type of pencils, J, K, and L, cost $0, 05, $0.10, and$0.25 each, respectively. If a box of 32 of these pencils costs a total of $3.40 and if there are twice as many K pencils as L pencils in the box, how many J pencils are in the box?
A.6
B.12
C.14
D.18
E. 20
13. Ben and Ann are among 7 contestants from which 4 semifinalists are to be selected. Of the different possible selections, how many contain neither Ben nor Ann?
A.5
B.6
C.17
D.14
E. 21
14. Which of the following could be the sum of the reciprocals of two different prime numbers?
A.
7
13
B.
10
21
C.
11
30
D.
23
50
E.
19
77
15.150,200,250, n which of the following could be the median of the 4 integers listed above?
I 175
II 215
III 235
A. I only
B. II only
C. I and II only
D. II and III only
E. I, II, and III
16. Which of the following fractions has a decimal equivalent that is a
terminating decimal?
A. 10/189
B. 15/196
C. 16/225
D. 25/144
E. 39/128
17. If 3
y≠and
3x
y
is a prime integer
greater than 2, x and y are integers, which of the following must be true?
I x y
=
II 1
y=
III x and y are prime integers
A. None
B. I only
C. II only
D. III only
E. I, and III
18. A certain fraction is equivalent to
2
5
.If the numerator of the fraction is increased by 4 and the denominator is double, the new fraction is equivalent to
1
3
. What is the sum of the numerator and the denominator of the original fraction?
A.49
B.35
C.28
D.26
E. 21
19. A wildlife preserve is being planned for 3,000 rhinoceroses. The preserve is to contain a total of 10,000 acres of watering area, plus 100 acres of grazing area for each rhinoceros. If the number of rhinoceroses is expected to increase by 10 percent, how many thousand acres should the preserve have in order to provide for the increased population?
A.340
B.330
C.320
D.310
E. 300
20. If it is 6:27 in the evening on a certain day, what time in the morning was is exactly 2,880,717 minutes earlier? (Assume
standard time in one location)
A.6:22
B.6:24
C.6:27
D.6:30
E. 6:32