Two events are mutually exclusive if they cannot occur at the same time.
When flipping a coin, the two events (heads and tails) are mutually exclusive.
What is the probability of flipping a coin and getting heads or tails?
There is a 100% chance the coin will land on either heads or tails.
When picking randomly from a deck of cards, the two events heart and king are not mutually exclusive.
When picking randomly from a deck of cards, what is the probability of choosing a card that is a heart or a king, but not both?
The probability of drawing a card that is either a heart or a king, but not both, is approximately 31%.