4/52
It is 3/13.
The probability is 0.25
The answer depends on how many cards are picked. It is 1 if you pick 49 cards without replacement. If only one card is picked at random, the probability is 1/13.
13/52
The probability of picking a black ace in one random draw from a normal pack of playing cards is 1/26.
The probability that a single card, drawn at random, is a 9 is 1/13.
It is 1/4.
The probability of picking a diamond out of a standard deck of 52 cards is 13 in 52, or 1 in 4, or 0.25.
"Playing cards" are chosen at random.
1/52
3 out of 13
If you pick enough cards, the probability is 1. For a single card, picked at random, the probability is 1/13.