If you a draw a card from a standard deck of 52 cards, what is the probability that the card will be an odd number?
If the Ace isn't odd,
In a standard deck of cards, there are 13 ordinals: 9 numbered cards 2-10, plus cards Jack, Queen, King, and Ace (which could be considered a 1). There is one of each ordinal in each of four suits: clubs, spades, hearts, diamonds.
The calculation then rests on whether we consider the Ace an odd card or not. I'll do the calculation both ways.
Ace is not odd
The ordinals 3, 5, 7, and 9 are odd. There are four of each (one for each suit) and so
Ace is odd
If we want to consider the Ace as a 1, then there are 5 ordinals that are odd,