417 Precalculus
Probability Unit II
Review Sheet
Name
Date
Period
Teacher
Problems:
1.
A family plans to have three children.
List the sample space.
1. Sample Space
What is the probability that:
2.
a.
all 3 will be girls?
a.
b.
all 3 will be boys?
b.
c.
2 boys and 1 girl?
c.
d.
at least one boy?
d.
e.
it won’t be 2 girls and a boy?
e.
The probability of snow tomorrow is 40%. Find the odds it will snow tomorrow.
2.
3.
Ten retired math teachers have formed a new organization. It’s desired to elect a president,
a vice–president, a secretary and a treasurer.
a.
b.
c.
How many possible ways are there to select
the officers?
3a.
What is the probability that Mr. Smith, one of
the teachers will be elected treasurer?
b.
What is the probability that he will be elected to
any of the four offices mentioned?
c
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4.
In a coin collection there are 9 pennies, 8 nickels, 12 dimes, 16 quarters, 11 half–dollars
and 4 dollar pieces. A coin is randomly selected from the collection by a blind–folded boy
who gets to keep the coin picked. What is the expected value?
4.
5.
A pair of dice is rolled. Depending upon the sum of the dots appearing on both dice, Jim can
win or lose money as shown in the chart below. What is the expected value?
Sum of dots
6 or 8 or 9
2 or 4 or 5
10
3 or 12
7 or 11
Outcome
win $6
lose $4
win $7
win $5
lose $1
5.
6.
What is the expected value of a fair game?
6.
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7.
8.
9.
A card is drawn from a standard deck of 52 cards. Find the probability that the card is
a.
a black four
b.
a king or an ace
b.
c.
a six or a club
c.
Two dice are rolled. Find the probability that
a.
one of the die shows a 3
b.
they show the same number
b.
c.
sum is more than 12
c.
d.
sum is 8 or sum is less than 6
d.
e.
sum is at least 8
e.
f.
sum is a multiple of 3
f. ___________________
8a.
A committee of 5 people is to be formed from a group of 7 men and 6 women.
a.
How many different committees can be formed?
b.
What is the probability that the committee will
consist of 3 men and 2 women?
b.
What is the probability that it will have at least
3 women?
c.
c.
10.
7a.
9a.
From a standard deck of 52 cards, 2 cards are selected. What is the probability that the
following occurs?
a. 2 black cards selected without replacement
b. 2 black cards selected with replacement
10a. __________________
b. ___________________
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11.
c. 1 red card and 1 spade
in any order selected without replacement
c. ___________________
d. 1 red card and 1 spade
in that order selected without replacement
d. ___________________
Mary turns on the T.V. The probability that the T.V. is HBO is 1/3, and the probability that it is
on TMC is 4/13. What is the probability that it is on either HBO or TMC?
11.
12.
Larry’s car will not start. Based upon past experience, Larry knows that the probability
that it is the battery is 0.65, the probability that it is the automatic choke on the carburetor
is 0.45, and the probability that it is both is 0.24. Find the probability that it is either
of these two problems.
12.
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13.
In a certain community, the probability that a married man is a college graduate is 5/14.
The probability that his wife is a college graduate is 3/7, and the probability that both the
husband and wife are college graduates is 1/7.What is the probability that either a man
or his wife are college graduates in this community?
13.
14.
A batter is now batting .200. In the next five times at bat, what is the probability of having
exactly 3 hits?
14.
15.
A coin is tossed four times. What is the probability of getting 2 heads and 2 tails?
15.
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16.
If a tack is dropped, the probability that it will land point up is 2/5. Ten tacks are dropped.
What is the probability of exactly 3 landing point up?
16.
17.
Mario is taking a multiple choice exam which consists of 5 questions. Each question has 4
possible answers. Mario guesses at every answer. What is the probability that he passes the
exam if he needs at least 4 correct answers to pass?
17.