SOLUTION: An urn B1 contains 2 white and 3 black balls and another urn B2 contains 3 white and 4 black balls. One urn is selected at random and a ball is drawn from it. If the ball drawn is

Algebra ->  Probability-and-statistics -> SOLUTION: An urn B1 contains 2 white and 3 black balls and another urn B2 contains 3 white and 4 black balls. One urn is selected at random and a ball is drawn from it. If the ball drawn is       Log On


   

Question 1100449: An urn B1 contains 2 white and 3 black balls and another urn B2 contains 3 white and 4 black balls. One urn is selected at random and a ball is drawn from it. If the ball drawn is found black, find the probability that the urn chosen was B1.
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


P((urn B1) AND (black)) = %281%2F2%29%283%2F5%29+=+3%2F10

P((urn B2) AND (black)) = %281%2F2%29%284%2F7%29+=+2%2F7

Then the probability that urn B1 was chosen, given that the ball is black, is %283%2F10%29%2F%28%283%2F10%29%2B%282%2F7%29%29+=+%283%2F10%29%2F%2841%2F70%29+=+21%2F41