What is Probability? Simple Definition and Examples

Probability is the measure of the likelihood or chance that a given event will occur. 

Some Important Key Concepts about Probability

The probability is expressed as a number between 0 and 1. 

• When the probability is 1, the event will occur 100% of the time.

• The closer to 1, the more likely the event will occur.

• When the probability is 0, the event will never occur.

• The closer to 0, the less likely the event will occur.

Probability of a Few Interesting Events

For example, we could find the probability for the following events: 

Let A be the event that it will snow in Norway in December

Let B be the event that a die will land on 4

Let C be the event that the universe will disappear tomorrow.

P(A) = 1 since there is always snow in Norway in December

P(B) = 1/6 since there are 6 possibilities and 4 is one of them

p(C) = 0 because the universe will not disappear tomorrow.