00:01
In this problem, it is said that in a box there are five red cards and six blue cards.
00:05
You reach into the box and you randomly draw one card.
00:09
We have been given three events and we need to find certain probabilities.
00:13
The first probability we need to find is the probability of r.
00:16
That is the probability that a red card is drawn.
00:19
Now this will be the number of favorable outcomes divided by the total number of outcomes.
00:23
The number of favorable outcomes is the number of red cards.
00:26
That is five.
00:27
And the total number of outcomes is the total number of outcomes is the total number of outcomes.
00:30
Number of cards in the box, there are five red cards, six blue cards, so five plus six gives us the total number of cards in the box.
00:37
So we end up with five by eleven, and so our answer is five by eleven.
00:43
Now consider the next one.
00:44
We need to find the probability of the event b, that is the probability of selecting a blue card.
00:50
Now once again, the total number of outcomes will be 11.
00:52
And this time the number of favorable outcomes is the number of blue cards, that is six.
00:57
And so this is our required probability, six by 11.
01:01
Next, consider the probability of e given b.
01:07
Now, this will be according to the definition of conditional probability, the probability of e and b divided by the probability of b.
01:16
Now, we just found the probability of b to be 6 by 11, and the probability of e and b will be the number of favorable outcomes divided by the total number of outcomes, which is once again 11...