I have to resolve this exercise:
I have 52 cards. I get 5 cards. Calculate the probability I get a poker hand of four-of-a-kind.
well I applied the formula ${52 \choose 5}=\frac{52!}{5!47!}$ to calculate every possible combination.but after here I don't know how can go ahead. Some help?
Edit
I made mistake.Now it's correct