What is the probability of drawing a king or a queen or a jack from a deck of cards?

The probability that you would get one of these cards is 12 /52.

What is the probability of drawing an ace or a black card?

However, The probability of getting a black card or an ace [which we may denote as P(black or ace)] is not P(black) + P(ace) since the former is 28/52 (there are 26 black cards and 2 red aces) while the latter is 26/52 + 4/52.

What is the probability of drawing a heart or an ace from a deck of 52 cards?

There is only one Ace of Hearts card in a deck of 52 cards. So, the probability of drawing a Heart and an Ace = 1/52.

What is the probability of drawing a king or a club or both from a deck of cards?

There are 52 card in a standard deck. The probability of getting a king or a club or both from a deck of cards should be calculated as: The probability of picking up a king is 4/52, since there are 4 king(K♦, K♠, K♥, K♣) in the deck.