Question

Sum of probabilities of mutually exclusive and collectively exhaustive events

Answer 1

When we will add all the possible events occured, it's is always equal to 1

Answer 2

Sum of probabilities of mutually exclusive and collectively exhaustive events is 1.

• Mutually exclusive events are ones that cannot occur at the same time.
• In other words the probability of occurrence of two mutually exclusive events at the same time is 0.
• Union of all collectively exhaustive events give us the sample space.
• In other words if at least one of the event is occurring, then the set is called collectively exhaustive.
• So, the union of mutually exclusive and collectively exhaustive events make all the possible events.
• Hence the sum will be equal to 1.