00:01
There are five blue, three red, and two yellow marbles.
00:04
If you draw three marbles, what is the probability that less than them will be red? that means either zero or one will be red.
00:16
And we want to do it with replacement and without replacement.
00:19
So let's see, less than two of them be red.
00:21
It means we need to find the probability that zero will be red and the probability that one will be red.
00:27
Let's start with with replacement.
00:29
So that means the probability of being red, how many do we have? 10? if no reds, it means we get everything else.
00:39
So that would be 7 or not red out of 10, 7 out of 10, 7 out of 10.
00:45
So we multiply that together and we get our probability.
00:48
The probability that at least one of them is red, the thing is we don't know which one.
00:53
So we have three different possibilities.
00:55
Red here or we could have red here or we could have red here or we.
01:02
We can have red here.
01:04
So probability of red is going to be three out of ten and then we're putting it back so these would be seven out of ten.
01:12
Now notice each one of these is going to be the exact same thing.
01:17
So we're going to basically multiply all of those together and get our answers and add them together.
01:25
So now we want to know what about it's without replacement.
01:30
We're going to do the same thing...