Probability is used in our day to day life, for example, when we toss a coin, we cannot anticipate whether it will be head or tail. That means we are uncertain about the event. Therefore, probability is how an event is likely to occur. The ratio of number of favorable outcome to the total number of outcome is known as Probability
The basic probability formula is given as,

Probability of an event = $\frac{number \ of \ favorable \ outcome}{total \ number \ of \ outcome}$.

Here are some of the probability examples below:

Question 1: There are 5 red and 1 green marbles in a bag. What is the probability of getting a red marble?
Solution:
Given:
Total marbles in the bag = 6,
Number of red marbles = 5

We know that,
Probability of an event = $\frac{number \ of \ favorable \ outcome}{total \ number \ of \ outcome}$.

So, 
Probability of getting red marble = $\frac{5}{6}$

Probability of getting red marble = 0.8

Therefore, the probability of getting red marbles is 0.8.

Question 2: When a die is thrown, find the probability of getting a "5" from that die.
Solution:
Given:
Total number of outcomes = {1, 2, 3, 4, 5, 6} = 6
Number of "5" in die = 1

We know that,
Probability of an event = $\frac{number \ of \ favorable \ outcome}{total \ number \ of \ outcome}$.

So, 
Probability of getting "5" = $\frac{1}{6}$

Therefore, the probability of getting "5" is $\frac{1}{6}$.