00:01
All right, so we're told that the sum, which i'll represent just as, or actually, i'll call the sum z, and that's of two random variables, x and y.
00:14
We're told that z is at least 1 ,200.
00:18
So we have z is greater than or equal to 1 ,200.
00:21
If that's the case, in fact, i'll call this event, e, the sample space, or actually i'll put it this way, the number of or the different possible ways that e could occur would be if we have x equals 6 ,000, so i'll put everything just in the lower form that we're given.
00:46
So z greater than are equal to 12.
00:48
We could have x equals 6 and y equals 6.
00:53
We could have x equals 18, y equals negative or actually no, we couldn't have y equals negative 12 because then they would add up to six.
01:04
So we could have x equals 6, y equals 18, y equals 6, x equals 18, or we could have x equals 18, y equals 18.
01:25
So we can find that the total probability of z being greater than or equal to 12 would be equal to, now i'm just going to crunch the numbers on screen here...