SOLUTION: An urn contains 5 red balls and 2 green balls. a ball is drawn. if it's green a red ball is added to the urn and if it's red a green ball is added to the urn.(the original ball is

Algebra ->  Probability-and-statistics -> SOLUTION: An urn contains 5 red balls and 2 green balls. a ball is drawn. if it's green a red ball is added to the urn and if it's red a green ball is added to the urn.(the original ball is       Log On


   

Question 903058: An urn contains 5 red balls and 2 green balls. a ball is drawn. if it's green a red ball is added to the urn and if it's red a green ball is added to the urn.(the original ball is not returned to the urn)then a second ball is drawn.what is the probability the second ball is red ?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
P(second all red) = both red + green then red = +%285C1%29%284C1%29%2F%288C2%29+%2B+%282C1%29%286C1%29%2F%288C2%29