00:01
First, we need to apply some rules of logic here to expand this expression into another expression that contains the information we know in the problem.
00:12
So first, this is a or b or c.
00:16
We first add each of them individually, and because we have n, we have to keep the n, so distribute the n.
00:23
So this is n of a plus n of b plus n, n of b, plus n of c.
00:34
Now we have to subtract the redundancies.
00:38
The redundancies are, so subtract n of a and b happening, a and b, minus n of a and c happening, a and c, minus the third redundancy of a, sorry, not a.
00:59
We already have a with b and c, this would be b with c, and then we have to add, because when canceling with these three redundancies, we have to consider the scenario in which the three of them happen at the same time.
01:14
So a and b and c.
01:19
And this is all information we are giving in the problem...