Download Probability Review

1.
In a local district, there are 1300 Democratic, 1100 Republican, and 400
Independent registered voters. If a voter is selected at random, what is the
probability to the nearest whole percent that the voter selected is Republican?
2.
What is the sample space when two coins are flipped consecutively?
3.
Find each of the following probabilities using the sample space for rolling a pair
of number cubes. Write the probabilities as fractions in lowest terms.
a.
P(sum equals 3)
c.
P(sum not equal to 12)
b.
P(same number on each)
4.
A bag contains marbles identical in every way but color. The bag contains 1 red, 2
blue, 3 green, and 4 orange marbles. Make a probability distribution that
represents the probabilities of choosing each color of marble from the bag. Write
the probabilities as fractions and as decimals.
1.
Give an example of mutually exclusive events.
2.
Suppose you roll a pair of number cubes. Find the probability that the numbers
showing are the same or that their sum is 11.
3.
Of the 200 seniors, 98 are boys, 34 are on the track team, and 20 are boys on the
track team. Find the probability that a student chosen at random is a boy or is on
the track team.
4.
What is the probability that either of two number cubes tossed simultaneously
shows a 3?
5.
How many seven-digit telephone numbers are possible if the first three digits are
268 in that order, the fourth digit is not 0, and the seventh digit is not 9?
6.
Bag A contains 5 red marbles, 6 green marbles, and 7 purple marbles. Bag B
contains 12 black marbles, 18 blue marbles, and 10 orange marbles. A marble is
chosen at random from each bag. Find the probability of selecting a red marble
from Bag A and a black marble from Bag B.
1.
A card is drawn from a standard deck of playing cards, replaced, and a second
card is drawn. What is the probability that the second card drawn is a spade?
2.
Suppose that you flip a coin and spin a spinner with a 50% red region, 25% blue
region, and 25% green region. Find each probability.
3.
4.
a.
P(heads and green)
c.
P(tails and red)
b.
P(heads and not green)
A bag contains 3 red marbles and 5 blue marbles. Samuel draws a marble from
the bag without looking, puts it into his pocket and then draws a second marble
without looking.
a.
Find the probability that both marbles Samuel drew from the bag are red.
b.
Find the probability that both marbles that Samuel drew at random are
the same color.
Find each probability.
a.
A spade is randomly drawn from a standard deck of playing cards on two
successive draws, given that the card is replaced.
b.
A spade is randomly drawn from a standard deck of playing cards on two
successive draws, given that the card is not replaced.
5.
A fair coin is tossed three times. Find P(heads, then heads, then heads).
6.
A student council sends 4 boys and 6 girls to the local school board meeting. Three
of the students will be interviewed. Find the probability that all three students
interviewed are girls.
1.
Find the number of ways to arrange 5 objects on a shelf that are chosen from a set of
7 objects.
2.
How many different 3-digit numbers can be made from the digits of 45678 if a digit
can appear just once in the number?
3.
If a school has lockers with 50 numbers on each combination lock, how many
possible combinations using three numbers are there?
4.
Seven horses are in a race. You want to predict which horse will finish first, then
second, and then third. How many different predictions are possible?
5.
For a study, 4 people are chosen at random from a group of 10 people. How many
ways can this be done?
6.
There are 12 boys and 14 girls in Mrs. A’s math class. Find the number of ways Mrs.
A can select a team of 3 students from the class to work on a group project. A team
consists of 1 girl and 2 boys.
7.
James is the sales manager for four local stores. During his workday, he visits each
of the stores (A, B, C, and D) exactly once. He tries to visit the stores in a different
order every day. How many different ways are there? Is this an example of
combinations or permutations?
8.
A school chess club has 10 members. Three students will be chosen at random to go
to a tournament. Is this an example of combinations or permutations? How many
different groups can be chosen?