Question

is it same
p(a or b) = p(a)+p(b)-p(a and b)
or
p(a and b ) = p(a)+p(b) -p(a or b)
i need to know that both are same and can we use them according to question

Answer 1

The first one is used to find the probability of two events when they are not mutually exclusive.

Answer 2

what about second

Answer 3

The second equation is not valid.

Answer 4

why is the second one not valid ?

Answer 5

x=A+B-y
is the same as
x+y=A+B
which is the same as
y=A+B-x