Question

A fair die is rolled once. [4 MARKS]
(i) What is the probability of getting a multiple of 2?
(ii) What is the probability of getting a prime number?

Answer 1

Each part: 2 Marks

When a die is rolled once, the possible outcomes are 1, 2, 3, 4, 5 and 6

$\Rightarrow$ Total numbers on the dice = 6

(i) Multiples of 2 are 2, 4, 6

$\Rightarrow$ Numbers of Multiples of 2 = 3

Probability of getting a multiple of 2 is

$P\left(E\right)=\frac{\text{Number of multiples of 2}}{\text{Total numbers on the dice}}$

$P\left(E\right)=\frac{3}{6}=\frac{1}{2}$

(ii) Prime numbers are 2, 3, 5

$\Rightarrow$ Numbers of Multiples of 2 = 3

Probability of getting a prime number is

$P\left(E\right)=\frac{\text{Number of prime numbers}}{\text{Total numbers on the dice}}$

$P\left(E\right)=\frac{3}{6}=\frac{1}{2}$