Mutually Exclusive Events

Two events are mutually exclusive if:

• they cannot happen at the same time
• they can happen at the same time
• they always happen 
• they never happen 

Two events are NOT mutually exclusive if:

• they cannot happen at the same time
• they can happen at the same time

• they always happen 
• they never happen 

Which formula do you use when two events are mutually exclusive?

• P(A or B) = P(A) + P(B)
• P(A or B) = P(A) + P(B) - P(both)
• P(A and B) = P(A) * P(B)
• P (A and B) = P(A) * P(B|A)

Which formula do you use when two events are NOT mutually exclusive?

• P(A or B) = P(A) + P(B)
• P(A or B) = P(A) + P(B) - P(A or B)
• P(A and B) = P(A) * P(B)
• P (A and B) = P(A) * P(B|A)

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

• Not Mutually Exclusive

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

• Not Mutually Exclusive

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

• Mutually Exclusive

• Not Mutually Exclusive

If a spinner is numbered 1 – 8, when you spin it the events of spinning an even number and a number less than 4 are ...

• Mutually Exclusive

• Not Mutually Exclusive

Sarah has 15 red chips, 12 blue chips, and 13 white chips. What is the probability that Sarah randomly selects a red or a white chip is an example of mutually ________ event.

• Mutually Exclusive

• Not Mutually Exclusive

Which of the following pairs of events is mutually exclusive?

• Cards: Aces and Spades

• Two dice: Odd and even

• Sit down and stand up

• Sit down and scratch your nose