What is the formula of probability?

The formula to find probability is

Probability = (Number of a Favourable outcome) / (Total number of outcomes) 

(number of elements in set A/number of times event A can occur) divided by (number of elements in the Universal set)

Probability of an event = (number of favourable outcomes) / (total number of outcomes)

Probability of event 'A' is equal to (Number of Event A occurred) divided by (Total Number of Events occurred in Sample Space):

P(A) = n(A)/n(S); where 'A' is Event 'A' Occurred and 'S' is Total Number of Events in Sample Space

Rule for addition- P(AuB)=P(A)+P(B)-P(AnB)

Probability = Outcome of an event/Total number of outcomes

Number of possible outcome / Number of total outcome

No. Of favourable conditions divided by total no. Of outcomes

Number of desired outcomes, over total possible outcomes.

Probability of a favourable event P(E) = (Number of favourable outcomes) ÷ (Number of Elements in Sample space). 

The most known formula of probability is division of the number of favorable events by the total number of possible events.