What is the probability of getting an even number when rolling a fair 6-sided die?                           [Page No. 165]

Total outcomes: $\{1, 2, 3, 4, 5, 6\} = 6$

Even numbers on the die: $\{2, 4, 6\} = 3$ outcomes.

$$P(\text{even}) = \frac{3}{6} = \frac{1}{2}$$

Concept Applied
Theoretical probability of an event =
$$\frac{\text{number of favourable outcomes}}{\text{total number of equally likely outcomes}}$$