00:02
All right, we have two identical pumps, which are numbered number one and number two.
00:05
We're given that the probability that both of them fail is 0 .01, and the probability that either of them fail is 0 .07.
00:13
And we're supposed to find the probability that one of them fails on its own.
00:19
So they give us some variables up here, but quite honestly, we don't need them to solve this problem.
00:24
Instead, i'm going to set some variables for some events.
00:27
So let a equal the event that pump number one fails.
00:38
And let's say b to be the event that pump number two fails.
00:51
All right.
00:52
Well, we have our addition rule.
00:55
So the probability of a union b equals the probability of a plus the probability of b minus the probability of a intersection b.
01:09
So let's think about this in context.
01:12
A union b is the event that both are sorry, a union b is the event that both are, sorry, a union b is the event that either of these happen, either pump one fails or pump two fails, well, that's this over here...