Cards and probability

I wanted to start my project on Probability by relating it to a common object we use pretty often and have a great knowledge of. Plus if you want to gamble later in life, probability is your friend ;).

So today we will be talking about cards and probabilities. First off to start a probability problem you need to know how to set it up. Here’s the formula we use to figure this out:

Probability is: the likelihood that a particular event will occur.

Probability of a possible outcome


Total number of items

So if we are using a deck of cards, we can figure out through knowledge that there are 52 cards, if not you can lay out the suits like I did in the is picture to figure it out.


there are 13 suits and 4 in each suit so therefore 4X13 =52

So the first problem we are going to do is finding the probability of getting a red card out of the deck of cards:

By looking at the picture below you can see each suit has 2 red cards. therefore if there are 13 suits that would be 13X2= 36. because there are 2 in each of the suits:


so the problem would be as follows:

Number of red cards                     26                               1                 I reduced the fraction

————————–         =   ————–   =             ————          because you always

total number of cards                    52                               2                reduce them by division

There are plenty more problems you can do with cards as well. Another example is:

How many face cards will you get out of a deck of cards?

There are 3 face cards (Jack, Queen, King) and each one has 4 suits (spades, clubs, hearts and diamonds) so therefore the problem would be 3X4 =12

So the problem would be 12/52 and when you reduce it, it would be 2/13.

Next time you go out to play cards. Remember some of these tips to help figure out the probability of getting what your looking for. 😀

Here’s an example of using probability and playing cards to make a venn diagram to illustrate the outcomes as well HERE