Question 1
Suppose an experiment is performed in which a coin is flipped 4 times. The resulting sample
space is
S = { hhhh, hhht, hhth, hthh, thhh, hhtt, htht, thht, htth, thth, tthh, ttth, ttht, thtt, httt, tttt }
Event A is defined as follows:
A = { hhtt, htht, thht, htth, thth, tthh, ttth, ttht, thtt, httt, tttt }
Event A can be expressed in words as “the event that
a) more than 1 tail is obtained”
b) less than 3 tails are obtained”
c) more than 2 heads are obtained”
d) less than 2 heads are obtained”
e) equal numbers of heads and tails are obtained”
Questions 2 and 3 are based on the following information:
Suppose a certain trait is associated with eye colour. Three hundred (300) people were
randomly selected and their eye colour and the absence/presence of the trait was recorded.
The number of people in each category is given in the table below.
Eye Colour
Blue Brown Other
Present 70 30 20
Trait
Absent 20 110 50
Question 2
What are the odds against randomly selecting a person who has brown eyes but does not
have the trait?
a) 1: 0.467
b) 1: 3.666
c) 1: 0.7857
d) 1: 0.214
e) 1: 0.3666
Question 3
, The odds against a person having the trait are
a) 1 : 1.5
b) 1 : 2.5
c) 1 : 1.6667
d) 1 : 0.6667
e) None of the above
Question 4
Which of the following statements best interprets the odds of passing Math 130 being 2 to
1?
a) There is a 2% chance of passing Math 130.
b) There is a 50% chance of passing Math 130.
c) For every 3 students, 2 are likely to pass Math 130.
d) There is a 67% chance of passing Math 130.
e) Twice as many students are expected to fail Math 130 as those who pass
Question 5
Suppose A and B are events such that P ( A ) >0 and P ( B )> 0. Events A and B are
independent if
a) P ( A )=P ( B )
b) P ( A ∩B )=0
c) P ( A ) + P ( B )=1
d) P ( B ) P ( A∨B ) =0
e) P ( A ∩B )=P ( A ) P ( B )
Question 6
Busi does not like going to the doctor so she will only go to the doctor 15% of the times that
she gets sick. If Busi goes to the doctor, there is an 85% chance that she will be given
antibiotics. What is the probability that next time Busi gets sick, she will go to the doctor
and will be given antibiotics?
a) 0.7
b) 0.1275
c) 1
d) 0.5667
e) 0.7225
Question 7