7 cards are selected at random from a pack of cards without replacement. What is the probability that exactly three of them are numbered cards (2 through 10)? If a hand of 13 cards is dealt from the...

7 cards are selected at random from a pack of cards without replacement. What
is the probability that exactly three of them are numbered cards (2 through 10)? If a hand
of 13 cards is dealt from the pack, what are the expectation and variance of the number of
numbered cards that it contains?