00:01
In this question, we're given that there are 10 balls numbered 1 through 10 in an end, and that 5 balls are randomly drawn without replacement.
00:10
Now, a denotes the event that exactly 2 odd -numbered balls are drawn, and that occur on odd -numbered draws from the earn.
00:18
Now, i'm going to let o denote the event and odd -numbered ball is chosen, and e denote the event and even -numbered ball is chosen.
00:27
Now, we want to find probability of a, so we need to list up a few mutually exclusive cases.
00:35
So the first case would be the first ball drawn is odd, second is even, third ball drawn is odd, fourth and fifth ball is even.
00:47
Or, now in probability n is times, set notation is intercept, all is plus, set notation is union.
00:56
So all will be plus.
00:58
Or the other mutually exclusive case would be the first ball drawn is even, second ball is even, third ball is odd, fourth is even and last ball is odd.
01:11
Or the last case would be the first ball is odd, second is even.
01:18
The third ball is even, fourth is even and the last is odd.
01:24
So these are the three mutually exclusive case for event a.
01:29
Now let's look at the first case here.
01:32
The first ball drawn is odd.
01:36
Now we know that at this point there will be five odd balls out of 10.
01:41
So that's the probability.
01:43
The first ball is odd...
