SOLUTION: Urn 1 contains 2 blue and 3 green balls. Urn 2 contains 4 blue and 3 green balls. A ball is randomly drawn from urn 1, without replacement, and then placed inside urn 2. A ball

Algebra ->  Probability-and-statistics -> SOLUTION: Urn 1 contains 2 blue and 3 green balls. Urn 2 contains 4 blue and 3 green balls. A ball is randomly drawn from urn 1, without replacement, and then placed inside urn 2. A ball       Log On


   

Question 1183861: Urn 1 contains 2 blue and 3 green balls. Urn 2 contains 4 blue and 3 green balls. A ball is randomly drawn from urn 1, without replacement,
and then placed inside urn 2. A ball is then drawn randomly from urn 2 and placed back in urn 1. If a ball is to be randomly drawn from urn 1,
what is the probability that the ball is blue?
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
I will go quickly over the details, and show the solution briefly.

You should be clever enough to see flow of the solution.

P%28bbb%29+=+%282%2F5%29%2A%285%2F8%29%2A%282%2F5%29+=+1%2F10
P%28bgb%29+=+%282%2F5%29%2A%283%2F8%29%2A%281%2F5%29+=+3%2F100
P%28gbb%29+=+%283%2F5%29%2A%284%2F8%29%2A%283%2F5%29+=+9%2F50
P%28ggb%29+=+%283%2F5%29%2A%284%2F8%29%2A%283%2F5%29+=+9%2F50

Therefore the probability of drawing blue from urn 1 the second time around is the sum of all preceding probabilities, or highlight%2849%2F100%29.