Math 1121 Quiz 2 Practice Name __________________________
1. Answer each question and give a brief explanation for each answer.
(a) If P(A) = 0.48, what is the value of P(not A)?
(b) If P(not A) = 0.75, what is the value of P(A)?
(c) Is it possible that P(A) = 17/3?
(d) Is it possible that P(A) = 3/17?
(e) Does P(A) + P(not A) always equal 1?
2. The probability of drawing a red ball from an urn is 5
23
. What is the probability that a red ball will
not be drawn from the urn?
3. The student Executive Cabinet consists of six members including Sarah and Michael. A reporter for
the student newspaper wants to contact any member of the cabinet and calls one at random.
(a) What is the probability that Sarah is called?
(b) What is the probability that Michael or Sarah is called?
(c) What is the probability that neither Michael nor Sarah is called?
4. An urn contains 8 balls identical in every respect except color. There are 4 blue balls, 3 red ones and 1
white one.
(a) If you draw one ball from the urn what is the probability that it is blue or white?
(b) If you draw two balls without replacing the first one, what is the probability that the first is red and
the second is white?
(c) If you draw two balls without replacing the first one, what is the probability that one ball is red and
the other is white?
5. A single six person jury must be selected from a pool of 15 jurors.
(a) How many ways can a group of six people be selected if they are not seated in any particular order?
(b) How many different groups of six people can be selected if the seating arrangement (in a row)
matters?
