<PRE><B>Question 312826</B>
 Suppose two balls are drawn at random from a bag containing 7 blue and 4 orange balls. 
A) if the first ball is replaced before the second ball is drawn wht is the probabily that both balls drawn are blue?
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If you replace the 1st ball before drawing the second the draw results
are independent.
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P(2 blue)= P(blue and blue) = P(blue)*P(blue) = (7/11)^2 = 49/121
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B)if the first ball is not replaced before the second ball is drawn, what is the probability that both balls are blue?
P(blue | blue) = (7/11)(6/10) = 7/11 * 3/5 = 21/55
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Cheers,
Stan H.
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