When picking a random card from a standard deck, what is the probability of drawing a card that is less than a 10 (and so not K, Q, J, 10)?
For a standard 52 card deck it's
A standard deck has 52 cards, so I'll answer first for 52 and then since the question has 54 as the question, I'll add in the 2 extra cards (I'll presume these to be jokers).
Within a standard deck, there are 13 ordinal cards (Ace, or 1, through 10, and then Jack, Queen, King) with each ordinal having 4 suits: spades, hearts, diamonds, clubs.
For the probability of picking a card less than 10, we're looking for cards 1 through 9 in each of the 4 suits:
The number of cards we can pick from is 52, and so the probability is:
If we add the 2 jokers, we end up with