If I have nine cards, 3 red, 4 blue, and 2 purple, what is the probability of drawing two of the same card?
If your question is under that case "without putting the firct card back", the answer is
There are three propabilities (getting two reds, getting two blues and getting two purples just after trial):
Total probability is the sum of these
This is under the condition of when you pick the first card, you do not put it back to the cards.
Your answer is