# Math Help - Probability of P(AnB')

1. ## Probability of P(AnB')

So it gives me values P(A)=0.5, P(B)=0.5 and P(AnB)=0.3
How do I find P(AnB')???

2. Try drawing a Karnaugh Map...

3. never heard of a Karnaugh map?

4. Originally Posted by calculuskid1
So it gives me values P(A)=0.5, P(B)=0.5 and P(AnB)=0.3
How do I find P(AnB')???
Note $P(A')=0.5 = P(B')$

Karnaugh maps & probability? - Yahoo! Answers

5. Hello, calculuskid1!

$\text{Given: }\;P(A)=0.5,\;\;P(B)=0.5,\;\;P(A \cap B)=0.3$

$\text{Find }P(A \cap B')$

Place the given information in a chart . . .

. . $\begin{array}{c||c|c||c|}
& B & B' & \text{Total} \\ \hline \hline
A & 0.3 & & 0.5 \\ \hline
A' & & & \\ \hline \hline
\text{Total} & 0.5 & & 1.0 \\ \hline \end{array}$

And we can fill in the empty cells:

. . $\begin{array}{c||c|c||c|}
& B & B' & \text{Total} \\ \hline \hline
A & 0.3 & 0.2 & 0.5 \\ \hline
A' & 0.2 & 0.3 & 0.5 \\ \hline \hline
\text{Total} & 0.5 & 0.5 & 1.0 \\ \hline \end{array}$

And now we can answer the question.