Kevin S. answered • 01/21/13
Tutor
5
(4)
Since there are a total of 16 socks, the probability of both socks being blue is
P(blue) = 6/16 * 5/15 = 30/240 = 1/8
The probability of both being grey is
P(grey) = 10/16 * 9/15 = 90/240 = 3/8
The probability that they match is
P(blue) + P(grey) = 1/8 + 3/8 = 4/8 = 1/2
Ryan Y.
tutor
Kevin's correct. I'll just provide an assist. The first factor is the probability of drawing a blue (or grey) sock. Now, once that sock is gone, how many blue (or grey) socks remain, and how many socks are left in total? Because the first sock is removed, it changes the probability of drawing the second sock. Think of the second factor as the probability of drawing a sock of a certain color, given that one has already been pulled.
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11/14/13
Catherine S.
09/06/13