# Thread: Venn diagrams

1. ## Venn diagrams

Hey guys

I got a question with Conditional probability and i want to display this on a Venn diagram.

Pr(A|B) = 1/3
Pr(A|B') = 3/4
Pr(B) = 2/5
Pr(A'nB')=1/10

Initially i used the rule and i got Pr(AnB) = 2/15

but then i tried to do it on a Kanaugh map to test it, it seems to be wrong.

can anyone please help?

2. Originally Posted by qwertyuiop
Hey guys

I got a question with Conditional probability and i want to display this on a Venn diagram.

Pr(A|B) = 1/3
Pr(A|B') = 3/4
Pr(B) = 2/5
Pr(A'nB')=1/10 Mr F says: This value is NOT consistent with the above data.

Initially i used the rule and i got Pr(AnB) = 2/15

but then i tried to do it on a Kanaugh map to test it, it seems to be wrong.

can anyone please help?
Why would you use a Karnaugh table? A tree diagram is clearly the prefered approach because of the information given about the conditional probabilities. The answer of 2/15 is consistent with

Pr(A|B) = 1/3
Pr(A|B') = 3/4
Pr(B) = 2/5

3. so there's something wrong with the question ?

4. Originally Posted by qwertyuiop
so there's something wrong with the question ?
Well, if Pr(A'nB')=1/10 is part of the question, then yes that would be the obvious conclusion from what I wrote earlier.