Answer:
There are 52 cards in a standard deck of playing cards.
However, the number of cards in a deck can actually be different, depending on the deck being used, the game being played, and what country you are in.
In a standard deck used for bridge, poker and other games, there are 52 cards (4 suits, 13 cards per suit). There are also two jokers, because some card games use one or two jokers in the game. So sometimes you could say there are 54 cards in the deck, even though most card games don't use the jokers.
In a pinochle deck there are 48 cards, using 2 sets of the top six cards (ace high) in each of the four suits.