The sample space \( S = {1, 2, 3} \) consists of three outcomes. The probability of each outcome occurring is \( \frac{1}{3} \).
To find the probability of picking number 2 or 3, we need to determine how many favorable outcomes there are for this event.
The favorable outcomes for picking either 2 or 3 are:
- Outcome 2
- Outcome 3
There are 2 favorable outcomes (2 and 3) out of a total of 3 possible outcomes (1, 2, and 3).
Thus, the probability of picking number 2 or 3 is calculated as follows:
\[ P(2 \text{ or } 3) = P(2) + P(3) = \frac{1}{3} + \frac{1}{3} = \frac{2}{3} \]
Therefore, the probability of picking number 2 or 3 in simplest form is:
\[ \frac{2}{3} \]