Question

How do we find probability of an event

Answer 1

Probability of and event is the percentage of chance of something to happen. In order to find it, you have to divide that one event by all the other events and you will get the percentage of chance.

Hope this helps!

Answer 2

Divide the number of desired outcomes by the total number of possible outcomes.

Here are some examples using an unbiased 6-number die with numbers 1 through 6 on its faces.

Example 1:

What is the probability of rolling a 5?

Number of ways of getting the desired outcome?  1, by rolling a 5.

Total number of possible outcomes: 6, any roll from 1 to 6.

Probability of rolling a 5:

p(5) = (number of desired outcomes)/(total number of outcomes)

p(5) = 1/6

Example 2:

What is the probability of rolling a number grater than 4?

The desired outcome is 5 or 6. The number of ways of getting the desired outcome is 2 since only a 5 or a 6 will work.

Total number of possible outcomes: 6

p(greater than 4) = 2/6 = 1/3