Question 947017
Suppose an opaque jar contains 5 red marbles and 10 green marbles. Two marbles are picked at random from the jar without replacing the first one.
 
The probability of getting a green marble first and a red marble second is:
(5/15)(10/14) = 50/(210) = 5/21
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The probability of getting one green and one red marble is:
# of red/green pairs = 5*10 = 50
# of random pairs:: 15C2 = (15*14)/(1*2) = 15*7 = 105
P(red/green pair) = 50/105 = 10/21
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Cheers,
Stan H.
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