So if we have 52 cards it would be easy to check the odds with a formula, here is the procedure:
P(Ace) is 4/52 = 1/13
P(Spade) is 13/52 = 1/4
P(Ace and Space) = 1/52
therefore P(Ace or Spade) = 1/13 +1/4 - 1/52 = 4/13 =0.30769230769230769230769230769231. that is the probability
