[tex]P(5)=\frac{1}{13}[/tex]
1) Considering that in one deck we have 52 cards, and we also have four number fives one per each: hearts, spades, clubs, and diamonds.
2) Then we can delimit our sample space as 52 and the event as 4, so we can write out the following:
[tex]P(5)=\frac{4}{52}=\frac{1}{13}[/tex]
Note that we could simplify that, dividing both by 4. And that's the answer.
