Probability question (quick, I hope)?

I have 462 ping-pong balls. 167 of them are red. If I choose 7 of them, without replacement (i.e. I don't put them back after choosing), what is the probability that all 7 are red? How do I solve this?

Thank you in advance!
Update: Thanks everyone for replying so quickly! I'll give the points (once the time limit lets me) to Hauk who answered with details first, but I appreciate everyone's help. Cheers.
4 answers 4