00:01
So we have the success on this first question of having two or more torpedoes hit.
00:06
And that would mean it would be sunk.
00:08
So we want, if two are fired, the likelihood of being sunk is to have a hit and a hit, so .16.
00:17
Now, if we're going to have fire three, we could have two hit, or we could have all three hit.
00:24
And if we have two hit, that means one also misses.
00:26
So that is binomial probability.
00:29
And we have that 3 choose 2 times the probability of success to the second times the probability of a failure.
00:36
Or, we can have all three hit.
00:39
And when we do that calculation, it comes out to be about a 35 % chance.
00:44
And then finally, we're now just increasing the number of torpedoes that are being fired.
00:53
Now we're up to n being 4.
00:56
So this, again, is a binomial setting.
00:58
And we want to have two or more hit.
01:02
So that's going to be 2, 3, or 4.
01:04
And we could find those three probabilities and add them together.
01:07
Or, i'm going to use my binomial cdf.
01:10
The complement of two or more is one or less.
01:14
So that is 0 and 1.
01:16
And this binomial cdf will do that calculation for me.
01:20
And that comes out to be about 52 .5%...