QUESTION: If the average (arithmetic mean) of a and b is 35 and the average (arithmetic
mean) of b and c is 65, what is the value of c − a?
(A) 90
(B) 60
(C) 30
(D) 10
(E) It cannot be determined from the information given.

Which of the following could be the median of a set consisting of six different
primes?
(A) 2
(B) 3
(C) 9.5
(D) 12.5
(E) 39


Which of the following series of numbers, if added to the set {1, 6, 11, 16, 21},
will not change the set's mean?
I. 1.50, 7.11, and 16.89
II. 5.36, 10.70, and 13.24
III. -21.52, 23.30, 31.22
(A) I only
(B) II only
(C) III only
(D) II and II only
(E) None


What is the minimum percentage increase in the mean of set X {-4, -1, 0, 6, 9} if
its two smallest elements are replaced with two different primes?
(A) 25%
(B) 50%
(C) 75%
(D) 100%
(E) 200%


If sets A and B have the same number of terms, is the standard deviation of set
A greater than the standard deviation of set B?
(1) The range of set A is greater than the range of set B.
(2) Sets A and B are both evenly spaced sets.
(A) Statement (1) ALONE is sufficient, but statement (2) alone is not
sufficient to answer the question asked.
(B) Statement (2) ALONE is sufficient, but statement (1) alone is not
sufficient to answer the question asked.
(C) BOTH statements (1) and (2) TOGETHER are sufficient to answer the
question asked, but NEITHER statement ALONE is sufficient.
(D) EACH statement ALONE is sufficient to answer the question asked.
(E) Statements (1) and (2) TOGETHER are NOT sufficient to answer the
question asked, and additional data are needed.



ANSWERS
QUES 1: B
QUES 2: E
QUES 3: C
QUES 4: D
QUES 5: E