Question 764686
either a hear or a diamond would be 13/52 + 13/52 = 26/52
p(a or b) = p(a) + p(b) - p(a and b)
p (a and b) would be the probability of drawing a heart and a diamond with one draw which is impossible, so the probability of p(a and b), in this case, is equal to 0.
you have 13 hearts in the deck and you have 13 diamonds in the deck and you have 0 cards that are both a heart and a diamond.