# Prob. Question

• Oct 29th 2006, 05:15 AM
classicstrings
Prob. Question
The chance Andrea is most valuable player (MVP) is 0.4. THe chance that her friend is runner-up is 0.3. If the chance that Andrea is MVP and Brigid is runner-up s 0.2, what is chance that Andrea is MVP or Brigid is runner-up or both?

I'm having trouble working out what we are after here.

Thanks!
• Oct 29th 2006, 06:17 AM
CaptainBlack
Quote:

Originally Posted by classicstrings
The chance Andrea is most valuable player (MVP) is 0.4. THe chance that her friend is runner-up is 0.3. If the chance that Andrea is MVP and Brigid is runner-up s 0.2, what is chance that Andrea is MVP or Brigid is runner-up or both?

I'm having trouble working out what we are after here.

Thanks!

P(A)=0.4,
P(B)=0.3
P(A & B)=0.2

find P(A v B).

P(A v B) = P(A) + P(B) - P(A & B) = 0.5

Draw a Venn diagram to see why this is so.

RonL
• Oct 29th 2006, 11:26 PM
classicstrings
Yes, the answer is correct, however i still have trouble understanding,

If P(A) = 0.4, this is the probability of Andrea getting MVP right?

Then how is P(B) = 0.3, isn't this saying probability of Brigit getting MVP is 0.3, when it is not, and it is her getting "runner up" which is 0.3?

What does A and B stand for here? I am confused... thanks.

With a Venn diagram, there is a circle name A then a circle name B. In the intersection is 0.2, in just the A part 0.2, so Pr(A) = 0.4, and just in the B part it is 0.1, so P(B) = 0.3.