homie

Kiakaha Wrote:
-------------------------------------------------------
> think about it like a Venn diagram -- P(A) and
> P(B) are the two overlapping circles. If you just
> add together A and B, you will be 'double
> counting' the part where they overlap, P(AB).
>
> So you have to add them together and then subtract
> P(AB) to get the answer.
>
> I agree the wording is tricky and designed to
> throw us off....but the thing to remember is that
> P(A) + P(B) - P(AB) covers the possibility of A,
> or B, or both (again, think of the venn diagram).
>
> hope that helps.

This is perfect! Great answer. I totally forgot about the overlapping and then the potential for double counting...

pg 444 for all those confirming.

Much appreciated.



Edited 1 time(s). Last edit at Sunday, May 29, 2011 at 01:10AM by Matori.