The events are said to be mutually exclusive if they cannot occur simultaneously in a single draw. Events such as tossing a head or a tail with a coin, drawing a queen or a jack from a pack of cards, throwing an even number or an odd number with a dice are all mutually exclusive events. Here, the occurrence of an event rules out the happening of the other event in the same experiment, i.e,. If we toss a coin, we can never get a head and a tail in the same toss. Ex : Suppose a card is drawn from a pack of cards and we define events as below : A : The card drawn is a spade ; B : The card drawn is a heart ; C : The card drawn is a king. A and B are mutually exclusive, since if a card is a spade, it cannot be a heart, i.e, if A occurs, B cannot occur and vice versa. On the other hand, events A and C are not mutually exclusive as the card can be the king of spades. Similarly for B and C, the card can be king of hearts.