Question

If a die is rolled once, the find the probability of getting an odd prime number.

Answer 1

If a die is rolled once then the sample space is $\{1,2,3,4,5,6\}$.

Among which $3,5$ are odd primes.

So the probability of getting an odd primes when a die is rolled is $\frac{2}{6}=\frac{1}{3}$.