Question 1156744
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The probability of drawing a spade is 1/4; the probability of another suit is 3/4.<br>
If the balls are drawn from the first box, the probability of getting 2 white balls and 1 black ball is {{{(C(7,2)*C(2,1))/C(9,3)}}}.<br>
If the balls are drawn from the second box, the probability of getting 2 white balls and 1 black ball is {{{(C(6,2)*C(4,1))/C(10,3)}}}.<br>
P(2 white and 1 black) = {{{(1/4)((C(7,2)*C(2,1))/C(9,3))+(3/4)((C(6,2)*C(4,1)/C(10,3)))}}}<br>
You can do the calculations....<br>