Use the following information to fill in the Venn Diagram below.
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120 people were asked if they liked Math, Science, or Social Studies.
56 like Math
43 like Science
35 like Social Studies
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18 like Math and Science
10 like Science and Social Studies
12 like Math and Social Studies
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6 like all three subjects
Science
Math
Social Studies
1.
How many people like Math only? _____
2.
How many people like Science only? _____
3.
How many people like Social Studies only? _____
Objective: Students will be able to
construct probability models, compute
probability of equal likely events and use
the addition rule to find probabilities
Example 1: A fair coin is tossed twice, what are the possible outcomes? List them
in a set. What is the probability that the outcome is HH? Create a probability
model.
Example 2: A coin is weighted so that heads is three times as likely to occur as
tails. Construct a probability model for this experiment.
PROBABILITY FOR EQUAL LIKELY OUTCOMES
P(E)=____________________________
Example 3: Calculate the probability that in a 3-child family there are 2 boys and 1
girl. Assume equal likely outcomes.
Example 4: One card is drawn from a well-shuffled deck of 52 cards. What is the
probability of drawing…
 P(ace) = ________
 P(face card) = _________
 P(a red 10) = ________
 P(NOT a diamond) = ______________
Example 5: Consider the experiment of rolling a single fair die. Let E represent
the event “roll an even number” and let F represent the event “roll a 1 or 2.”
 Write the events E and F
 Write out the event E or F
 Compute P(E) and P(F)
 Compute P(E  F)
 Compute P(E  F)
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Example 6: A card is chosen from a well-shuffled deck of 52 cards. What is the
probability that the card will be:
 a king or a queen?
 a red jack or a black king?
 a face card or a card with a prime number?
 an even card or a red card?
 a spade or a jack?
Example 7: Look at the solution to the following problem and see if you can find
the error. Correct the error to find the right answer.
P(drawing an ace OR a black card) = P(ace) + P(black) =
4
26 30 15
+
=
=
52 52 52 26
Example 8: If P(E)=0.2, P(F)=0.3, and P(E  F)  0.1, find P(E  F) .
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PROBABILITY OF MUTUALLY EXCLUSIVE EVENTS
Look at your Venn Diagram and find
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P(M)=
P(S)=
P(SS)=
P(SS  M) =
P(S  M) =
P(M) =