<PRE><B>Question 691029</B>
A box contains 3 red, 5 black and 2 white balls. One ball is drawn randomly from the box. After putting the ball back into the box, one ball is again drawn randomly. 
Find the probability that the 2 balls drawn are of different colours
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# of ways to succeed: 10C2 - [3C2+5C2+2C2] = 45-[3+10+1] = 31
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# of possible pairs: 10C2 = 45
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P(2 of different colors) = 31/45 
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Cheers,
Stan H.
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