Addition Rule!
Probability (Cards)
Probability (Dice)
Mutually Exclusive?
All Notation
100
What's the equation for the Addition Rule?
P(AorB) = P(A) + P(B)
100

Probability of drawing a 2 (as a percent)

approx. 7.7%

100

the probability of rolling a 2  (give answer as a fraction)

1/6

100
How do you know if two events are mutually exclusive?
If the probability of the two events both occurring is 0.
100

In words, what does this mean: P(A ∩ B) 

Probability of A intersect B

200
Given events A and B, when is it appropriate to use the Addition Rule that subtracts out the P(AandB)?
When the two events are mutually exclusive.
200

Probability of drawing the Queen of Hearts?

1/52

200

Probability of an even number or a 1

(give as a percent)

about 67%

200
If P(A) = 0.35, P(B) = 0.68, and P(AandB) = 0.18. Are these events mutually exclusive? Why or why not?
No, because P(AandB) does not equal 0.
200

S= {1, 2, 3 ,4, 5, 6, 7, 8, 9,10}

A = {2, 4, 6, 8, 10}

B = {3, 6, 9}

What is P(A U B) ?

7/10

300
The probability that a Sophomore has taken computer class is 0.35 and the probability that they've taken Science is 0.83. The probability that they've taken both is 0.29. What's the probability that they've taken either?
0.89
300

Probability of drawing a 2,3 or 4 (as a fraction)

3/13

300

Probability of rolling an 8 on a single die

0

300
The Junior class at BInCA consists of 80 students. 14 have a GPA over 3.5 and 28 have a GPA between 2.5 and 3.49. Are these two events mutually exclusive?
Yes, they share no outcomes in common.
300

S= {1, 2, 3 ,4, 5, 6, 7, 8, 9,10}

A = Evens

B = Multiples of 3

What is P(A')?

5/10

400
The probability that a Sophomore has taken computer class is 0.35 and the probability that they've taken Science is 0.83. The probability that they've taken both is 0.29. What's the probability that they've taken neither?
0.11
400

Probability of pulling any 4 OR a heart (as a fraction)

4/13

400

A = Evens

B = Multiples of Three

P(A U B)?

2/3

400

You interview 30 students. 12 play sports and 18 have siblings. 9 play sports and have siblings. Are these events mutually exclusive? Why or why not?

No. The probability of sports and siblings is greater than 0.

400

S= {1, 2, 3 ,4, 5, 6, 7, 8, 9,10}

A = {2, 4, 6, 8, 10}

B = {3, 6, 9}

P(A ∩ B)  ?

1/10

500

In a standard deck of cards, what is the probability of pulling a Red Face Card, written as a percent?

62%

500

Probability of not an ace (as a percent)

about 92%

500

A = Evens

B= Multiples of 3

P(A ∩ B) :?


1/6

500
The probability that teachers at BI like rap is 0.64. The probability that the teachers like country music is 0.71. The probability they like both is 0.22. Are these events mutually exclusive? Why or why not?
No, because the probability they like both is not zero.
500

You interview 30 students. 12 play sports and 18 have siblings. 9 play sports and have siblings.What is 

P(play sports or have siblings)?

7/10

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