Probability Formula
The probability formula is used to find the probability of an event. Probability can be defined as the likelihood of an event to happen. It is the chance of predeciding the possibility of an event to happen. It can be calculated by probability formula by simply dividing the favorable number of outcomes by a total number of outcomes. The value of the probability of an event to happen can lie between 0 and 1 because the favorable number of outcomes can never cross the total number of outcomes. Also, a favorable number of outcomes cannot be negative. The probability formula along with solved examples is explained below.
What is the Probability Formula?
The probability formula defines the likelihood of the happening of an event. It is the ratio of favorable outcomes and total favorable outcomes. The probability formula can be expressed as,
Probability = (Favorable Outcomes)/(Total Favourable Outcomes)
P(A)=(n(A))/(n(s))
Where,
 P(A) = Probability of an event “A”
 n(A) = number of favorable outcomes
 n(S) = total number of events in sample space

Example 1: Find the probability of getting a face card from a standard deck of cards using probability formula.
Solution
To find:
Probability of getting a face card
Given: Total number of cards = 52
Number of face cards = Favorable outcomes = 12
Using Probability Formula,
Probability = (Favorable Outcomes)/(Total Favourable Outcomes)P(face card) = 12/52
m = 3/13
Answer: The probability of getting a face card is 3/13

Example 2: Find the probability of getting a number less than 5 when a dice is rolled by using probability formula.
Solution
To find:
Probability of getting a number less than 5
Given: Sample space = {1,2,3,4,5,6}
Getting a number less than 5 = {1,2,3,4}
Therefore, n(S) = 6
n(A) = 4
Using Probability Formula,
P(A)=(n(A))/(n(s))p(A)=4/6
m=2/3
Answer: Probability of getting a number less than 5 is 2/3.