Could someone please just give me a hint as to how I could prove this:

{(A∩B)’} = 1+P{A∪B} – P{A}– P{B}

Thanks.

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- Aug 24th 2008, 03:22 PMkid funky friedset proof
Could someone please just give me a hint as to how I could prove this:

{(A∩B)’} = 1+P{A∪B} – P{A}– P{B}

Thanks. - Aug 24th 2008, 03:48 PMPlato
- Aug 24th 2008, 06:48 PMkid funky friedYes..
Yes, a big THANK YOU, Plato!

Kid - Sep 2nd 2008, 01:36 AMban26ana
- Sep 2nd 2008, 01:54 AMMoo
There's a property (I don't know the name...) that says :

You can see it on a Venn diagram. If you add A and B, you'll add twice

http://upload.wikimedia.org/wikipedi..._A_union_B.png

This is why

denotes the complement - see here : Complement (set theory - Wikipedia, the free encyclopedia)

And we have

So :

... :p - Sep 2nd 2008, 02:04 AMban26ana
Thanks Moo. I found the theorem in my book that says P(A) = 1 - P(A'). Is that the same one that makes P(A' *intersect* B') = 1 - P(A U B)?

- Sep 2nd 2008, 02:15 AMMoo
- Sep 2nd 2008, 02:17 AMban26ana
Thanks again Moo. I get it!