SOLUTION: One bag contains 5 blue balls and 4 green balls. A second bag contains 2 blue balls and 5 green balls. One ball is selected at random from the first bag and placed in the second ba

Algebra ->  Permutations -> SOLUTION: One bag contains 5 blue balls and 4 green balls. A second bag contains 2 blue balls and 5 green balls. One ball is selected at random from the first bag and placed in the second ba      Log On


   



Question 1133552: One bag contains 5 blue balls and 4 green balls. A second bag contains 2 blue balls and 5 green balls. One ball is selected at random from the first bag and placed in the second bag. If a ball is drawn from the second bag, what is the probability that it is a green one?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
5/9 chance the second bag will have 3 blue balls and 5 green balls, and the probability of a green draw from that bag is (5/9) for first* (5/8) or 25/72
4/9 chance the second bag will have 2 blue balls and 6 green balls, so probability of green will be (4/9)(6/8)=1/3 (24/72)
The probability overall is the sum or 49/72. This is between 5/8 and 6/8 as expected.