SOLUTION: An urn contains 5 red balls and 3 green balls. A ball is drawn randomly and 6 more of the same color are added to the urn. Then another ball is drawn. Let R1= event ball # is red.

Algebra ->  Probability-and-statistics -> SOLUTION: An urn contains 5 red balls and 3 green balls. A ball is drawn randomly and 6 more of the same color are added to the urn. Then another ball is drawn. Let R1= event ball # is red.       Log On


   

Question 1026170: An urn contains 5 red balls and 3 green balls. A ball is drawn randomly and 6 more of the same color are added to the urn. Then another ball is drawn. Let R1= event ball # is red. G1= even the ball # is green. Find Pr(R1|R2)
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
P(R1|R2) = P(R1∩R2)/P(R2)
=P(R1∩R2)/(P(R1∩R2)+P(G1∩R2)) = %2850%2F104%29%2F%2850%2F104%2B15%2F104%29+=+50%2F65+=+10%2F13
Note that P(R1∩R2) = P(R2|R1)*P(R1) = %285%2F8%29%2A%2810%2F13%29+=+50%2F104
and P(G1∩R2) = P(R2|G1)*P(G1) = %283%2F8%29%2A%285%2F13%29+=+15%2F104.