PROBABILITY 2

Given the interval of 1-12 inclusive, Find the probability of having an even number or a prime number.

Solution

This is a non-mutually exclusive event.

n(S) = number of sample space = 12

Let P(E)= probability of even numbers = ⁶/12

Let P(R)= probability of prime  numbers = ⁵/12

P(EnR) = probability of having both even and prime numbers= ¹/12

∴ P(EuR) = P(E) + P(R)  - P(EnR).

 P(EuR) =  6  +  5 – 1

                12    12   12

P(EuR) =  11  -   1 

                12     12  

P(EuR) =  10 

                12      

Hence probability of an even number or a prime number is ^5/6.

TRY THIS........

Given the interval of 1-15 inclusive, find the probability of having an even number or a prime number.