SOLUTION: In a box there are 9 red balls and 4 green balls. Part a. Two random balls are taken one-after-another from that box, with replacements(which means that each taken ball is insta

Algebra ->  Probability-and-statistics -> SOLUTION: In a box there are 9 red balls and 4 green balls. Part a. Two random balls are taken one-after-another from that box, with replacements(which means that each taken ball is insta      Log On


   

Question 1198371: In a box there are 9 red balls and 4 green balls.
Part a. Two random balls are taken one-after-another from that box, with replacements(which means that each taken ball is instantaneously replaced by an identical ball). What is the probability that both of these balls are red?
Part b. Two random balls are taken from that box without replacements (which means that what is taken is gone). What is the probability that both of these balls are red?
Answer by ikleyn(52786) About Me  (Show Source):
You can put this solution on YOUR website!
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                                Part (a) 

    P = %289%2F%289%2B4%29%29%2A%289%2F13%29 = %289%2F13%29%5E2 = 81%2F169 = 0.4793 (rounded).    ANSWER

Part (a) is complete.


                                Part (b) 

    P = %289%2F13%29%2A%288%2F12%29 = %289%2F13%29%2A%282%2F3%29 after reducing = 18%2F39= 0.4615  (rounded).    ANSWER

Part (b) is complete, too.

Solved.