Suppose a card is drawn from a deck of 52 playing cards. what is the probability of drawing a 3 or a king?
In a full 52-card deck, there are 4 kings and 4 3's, which do not overlap. Therefore the total number of "successes" is 4+4=8 out of a 52-card deck. => The probability of drawing a 3 or a king out of a 52-card deck is 8/52=2/13.