Step 1: List all possible outcomes.
The total number of cards is \( 10 \), numbered as \( \{1, 2, 3, 4, 5, 6, 7, 8, 9, 10\} \).
Step 2: Identify favorable outcomes.
The event involves drawing a card that is:
An even number: \( \{2, 4, 6, 8, 10\} \)
A multiple of 5: \( \{5, 10\} \)
The union of these two sets is \( \{2, 4, 5, 6, 8, 10\} \), as \( 10 \) is common to both sets.
Step 3: Count the favorable outcomes.
The number of favorable outcomes is:
\[
|\text{Favorable outcomes}| = 6
\]
Step 4: Calculate the probability.
The probability is given by:
\[
P(\text{Favorable outcome}) = \frac{\text{Number of favorable outcomes}}{\text{Total outcomes}} = \frac{6}{10}
\]