00:01
All right, here we have a card.
00:02
It's selected at random from a standard deck of 52 cards.
00:04
And so we want to find the probability of each event.
00:07
Let's look at number a, the probability of selecting a black suit or a three.
00:12
So a black or a three.
00:15
Well, how many suits are black? well, there's two out of our four suits.
00:21
And how many of them are three? so actually, the way that we should say this is out of 52 cards.
00:27
So we're going to say out of 52 cards, how many of them are.
00:30
Are black.
00:31
Well, that's going to be half of them, which is going to be 26.
00:34
26 of them are black.
00:36
Now, how many of them are threes? there's going to be four threes, so four out of 52.
00:41
However, there are two black threes.
00:45
And so since we've counted them here, and we've counted them here as well, we're going to subtract two out of 52 from this.
00:52
So really what we have is 26 plus two out of 52, and that's going to be equal to 28 out of 52, which reduces, doesn't it? 28 out of 52, 28 divided by 52, that reduces to 7 out of 13.
01:09
So that's going to be our final answer for number a.
01:13
Now let's look at number b, randomly selecting a 4 or a face card.
01:19
All right, so we're going to say the probability of 4 or a face card.
01:25
So how many 4 is? do we have? well, this is going to be, well, there are four fours out of 52 cards.
01:31
Or a face card.
01:33
Well, none of the cards are both four and a face card.
01:37
So we can just say, well, how many face cards do we have? well, we have jacks, queens, kings, and aces...