For the first player:
The total number of possible hands of 13 cards from a deck of 52 is 52C13.
The total number of possible hands for this player that contains one ace and twelve other cards:
4C1·48C12 (which is choosing 1 ace from 4 aces and 12 other cards from the 48 remaining cards)
So, the probability for the first person getting one ace is: ( 4C1·48C12 ) / 52C13
For the second player:
Probability = ( 3C1·36C12 ) / 39C13
because: there are only 3 aces left, only 36 other cards left, and only a total of 39 cards left.
For the third player:
Probability = ( 2C1·24C12 ) / 26C13
because: there are only 2 aces left, only 24 other cards left, and only a total of 26 cards left.
For the fourth player:
Probability = ( 1C1·12C12 ) / 13C13
because: there is only 1 ace left, only 12 other cards left, and only a total of 13 cards left.
Multiply these four probabilities together to get the total probability. ...