00:01
One card is drawn from an ordinary deck of cards.
00:04
We want the probability that the card we draw is a 3, or a 4, or a hearts, or a clubs.
00:12
Okay, so of course we have to think, what do we do about the overlap? what if we get the 4 of clubs? well, typically when you have or, overlap is fine.
00:22
So it's 3 or 4 or hearts or clubs, or any combination of these.
00:27
So what we're going to do is look at how many cards meet this criteria.
00:30
Because we have 52 cards and each card is equally likely to come up.
00:41
Now, remember for probability distributions, if you take the probability of every outcome, add them all up, the sum is 1, or 100%.
00:51
When i pick a card, i am 100 % sure i am going to get a card, one of the 52 available.
00:58
And since they're all equally likely, they share this probability amongst themselves equally.
01:04
So each card has a 1 in 52 chance of coming up.
01:09
So for this to work, i'm just going to make a fraction, where i have all of the cards on the denominator, and the number that meets my criteria on the numerator.
01:18
When you have or involved, the important thing is make sure we don't double count any cards.
01:26
So, first of all, how many hearts and clubs are there? well, there are 13 of each, there are 52 cards, 13 of each suit, hearts, clubs, spades and diamonds.
01:36
So we have 26 already accounted for.
01:41
And now i want the 3 of diamonds, the 3 of spades, the 4 of diamonds and the 4 of spades...