1. Below are the grades from a randomly selected class
4
3
2
1
Boys
2
10
2
3
Girls
1
7
6
2
a. What is the probability of picking a girl who has a 3 in the class?
b. What is the probability of picking a boy given that the student has
a 2?
c. What is the probability of picking a student who has a 3 or higher
in the class?
2. Explain whether the two events are independent.
a. P(A) = .4 P(B) = .3
P(A and B) = .18
3. A school carnival game uses the spinners below. A player of this game wins if both
spinners stop in a yellow section. The player loses otherwise. What is the probability
that one can win the game? Assume parts are evenly divided.
yellow
yellow
A
4. A is the number of students who play
sports after school. B is the number of students
who are part of clubs.
B
19
32
21
27
a. What is the probability of choosing someone who is
part of a club or play sports after school?
b. What is the probability of choosing someone who
play sports but does not belong to a club?
5. Alicia and Barry are taking turns flipping a coin. When Alicia flips the coin, it
lands on heads four times in a row. Should she suspect that there is something
wrong with the coin?
a. No. While the probability of a coin landing on heads four times in a row is small,
it is possible.
b. No. The coin should alternate heads and then tails, so Alicia should always get
heads.
c. Yes. The coin should have landed on heads twice and tails twice.
d. Yes. It is impossible for a fair coin to land on heads four times in a row.
6. There are 5 books in a shelf. How many different ways can the book be
rearranged?
7. How many groups can be form if 4 people are chosen from a group of 9 people?
8. How many different ways can 6 people be chosen from a group of 10?
9. How many different combinations can be form from a menu that consists of 4
appetizers, 5 dishes, and 2 desserts?
10. Sarah wanted to know how many of her fellow students have at least one cat at
home. She randomly sampled 30 students from her school and 11 of them answered
yes. What is the approximate proportion of students who have at least one cat?