To find the probability of rolling a 1 or a 5 on a standard six-sided die, we start by considering the total number of outcomes and the number of favorable outcomes.
A standard die has six faces, so the total number of possible outcomes when rolling the die is 6.
The favorable outcomes for rolling a 1 or a 5 are:
- Rolling a 1
- Rolling a 5
There are 2 favorable outcomes.
To calculate the probability, we use the formula:
\[ \text{Probability} = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}} \]
Substituting the values we have:
\[ \text{Probability} = \frac{2}{6} = \frac{1}{3} \]
Thus, the probability of rolling a 1 or a 5 on a standard die is \(\frac{1}{3}\).