00:01
Hello students, in this question the probability of intersection of two events a and b is given by p of a intersection b.
00:06
So here the probability of the union of a and b is given by p of a union b.
00:11
So it is equal to p of a plus p of b plus, so p of b minus p of a intersection b.
00:20
Now let's consider the case when a and b are mutually exclusive events, meaning that they cannot both occur at the same time.
00:28
So in this case p of a intersection b equal to 0.
00:32
So if a and b are also complementary events, meaning that the occurrence of one event guarantees the non -occurrence of other events.
00:39
Then p of a plus p of b equal to p of a plus p of b equal to 1.
00:44
So in this case the probability of the union of a and b is probability of a union b equal to p of a plus p of b minus p of a intersection b.
00:54
So it is equal to p of a plus p of a plus p of b minus 0 minus 0.
01:08
It is equal to p of a plus p of b.
01:11
So and here it is equal to 1.
01:15
So since p of a intersection b equal to 0, p of a union b the probabilities are not equal.
01:20
However, let's consider another case where a and b are the same events...