text: # Thread: Finding Probability
  
  1. ## Finding Probability
  
  I am experiencing difficulties with the following problem. I don't know how to find the intersection probability of Pr(AnBcomplement). This is just for the first row. I found intersection of a and b which is 0.4, I also found A complement which is 0.3 and b complement which 0.4. Any help would be greatly appreciated.
  
  2. ## Re: Finding Probability
  
  Hi,
  
  Notation: B* = complement of B
  
  Remember that you can use: P(A) = P(A and B*) + P(A and B)
  
  For example for the first row:
  
  we know: Pr(A) = 0.7, Pr(B)=0.6 and Pr(AUB)=0.9
  
  P(AUB) = P(A)+P(B)-P(A and B)
  
  0.9 = 0.7+0.6 -P(A and B)
  
  P(A and B) = 0.4
  
  P(A and B*) = P(A)-P(A and B) = 0.7 - 0.4 = 0.3
  
  P(B and A*) = P(B)- P(B and A) = 0.6 -0.4 = 0.2
  
  Let me know if you need more help
  
  3. ## Re: Finding Probability
  
  Originally Posted by Solid8Snake
  I am experiencing difficulties with the following problem. I don't know how to find the intersection probability of Pr(AnBcomplement). This is just for the first row. I found intersection of a and b which is 0.4, I also found A complement which is 0.3 and b complement which 0.4. Any help would be greatly appreciated.
  That is a bad file. Word will not open it. Just type out your question.
  
  4. ## Re: Finding Probability
  
  Did i help you ? (the file opens right)
  
  Thanks
  
  5. ## Re: Finding Probability
  
  Originally Posted by MathTutor2013
  Did i help you ? (the file opens right)
  @MathTutor2013
  I take it from your screen name you fancy yourself a tutor for mathematics.
  Then why don't you bother to learn the standard mathematics protocol for mathematics type-setting LaTeX?
  Don't you think that $P(A\cup B) = P(A)+P(B)-P(A\cap B)$ looks much more professional that P(AUB) = P(A)+P(B)-P(A and B)?
  
  That code is simple [TEX]P(A\cup B) = P(A)+P(B)-P(A\cap B)[/TEX].
  
  On the tool bar the $\Sigma$ gives the [TEX] [/TEX] wrap.
  
  You can use this as a reference.
  
  6. ## Re: Finding Probability
  
  Thank you very much, it's all clear now.