A box contains 6 red balls and 5 green balls. three balls are selected at random from this box "with replacement". what is the probability that exctly two of the three balls are green?
-------------------------------------------- Given information -------------------------------------------- Red balls = 6 Green balls = 5
-------------------------------------------- Find total -------------------------------------------- Total balls = 6 + 5 Total balls = 11
-------------------------------------------- Find probability -------------------------------------------- G = green R = red P (R+ G + G) = 6/11 x 5/11 x 5/11 = 150/1331 P (G +R + G) = 5/11 x 6/11 x 5/11 = 150 /1331 P (G +G + R) = 5/11 x 5/11 x 6/11 = 150 /1331 Total probability = 150/1331 + 150 /1331 + 150 /1331 = 450/1331
-------------------------------------------- Ans: The probability is 450/1331 --------------------------------------------
