Question

the probability of a prime number when a standard dice is rolled is

Explanation:

Step1: Identify prime - numbers on a dice

The numbers on a standard dice are 1, 2, 3, 4, 5, 6. The prime numbers among them are 2, 3, 5.

Step2: Calculate probability

The probability formula is $P(A)=\frac{n(A)}{n(S)}$, where $n(A)$ is the number of favorable outcomes and $n(S)$ is the total number of outcomes. Here, $n(A) = 3$ (the number of prime - numbers) and $n(S)=6$ (the total number of numbers on the dice). So $P=\frac{3}{6}=\frac{1}{2}$.

Answer:

$\frac{1}{2}$