To find the probability of both events A and B occurring at the same time (their joint probability), we can use the formula for independent events:
\[ P(A \text{ and } B) = P(A) \times P(B) \]
Given that \( P(A) = 0.3 \) and \( P(B) = 0.25 \), we can substitute these values into the formula:
\[ P(A \text{ and } B) = 0.3 \times 0.25 \]
Calculating this gives:
\[ P(A \text{ and } B) = 0.075 \]
So, the probability of events A and B happening at the same time is \( \boxed{0.075} \).