Addition Rule for Mutually Exclusive Events

Mutually exclusive events are those that

• happen at the same time

• cannot happen at the same time

Tags

CCSS.HSS.CP.B.7

If you are picking a card randomly from a deck of cards, the events of picking an ace and picking a 3 are mutually exclusive.

• True

• False

Tags

CCSS.HSS.CP.A.1

CCSS.HSS.CP.B.7

If events A and B are mutually exclusive, what is P(A and B)?

• 0.50

• 0

• 1

• 0.75

Answer explanation

If events are mutually exclusive, they cannot happen at the same time. The probability would be 0

Tags

CCSS.7.SP.C.5

CCSS.7.SP.C.8

A day of the week is chosen at random. What is the probability of choosing a Monday or Tuesday?

• 1/7

• 2/14

• 2/7

• None of the above

Tags

CCSS.HSS.CP.B.7

If you are picking a card randomly from a deck of cards, the events of picking a jack and picking a heart are mutually exclusive.

• True

• False

Answer explanation

There is a Jack of Hearts, so the events can occur together

Tags

CCSS.HSS.CP.A.1

When rolling a single die, the events of rolling an even number and rolling a 5 are mutually exclusive.

• True

• False

Tags

CCSS.HSS.CP.A.1

CCSS.HSS.CP.B.7

There are 20 roses in a vase. 12 are red roses, 5 are yellow roses and 3 are white roses. Felix takes a rose, at random, from the vase.

What is the probability of him choosing a yellow rose or a white one?

Answer explanation

There are 5 yellow roses and 3 white ones. Add 5/20 + 3/20 = 8/20 = 2/5

Tags

CCSS.HSS.CP.A.1

CCSS.HSS.CP.B.7

There are 12 red roses, 5 yellow roses and 3 white roses in a vase. Felix takes a rose, at random, from the vase.

What is the probability of him choosing a red or a white rose?

Answer explanation

P(red or white) = P(red) + P(white) 12/20 + 3/20 = 15/20 reduce the fraction to 3/4

If P(A) = 0.25, P(B) = 0.50, and P(A or B) = 0.65, are the events A and B mutually exclusive?

• Yes since P(A or B) = 0

• Yes since P(A) + P(B) = 0.75

• No since P(A and B) is not gven

Tags

CCSS.HSS.CP.B.7

In a landfill, there is a 27% chance that a piece of trash is recyclable plastic, a 54% chance that the item is biodegradable, and a 9% chance that the item is neither of these things. Pick of piece of trash at random. What is the probability that it is recyclable plastic or biodegradable?

• 81%

• 21%

• 54%

• 63%

Tags

CCSS.HSS.CP.B.7