# Thread: Prob. Question

1. ## 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!

2. 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

3. 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.