.)A bag has 7 red marbles, 8 blue marbles and 3 black marbles. What is the probability of picking a blue marble, replacing it, a
nd then picking a red marble? Answer a. 14/81 b. 7/108 c. 2/27 d. 1/9 2.)A bag has 7 red marbles, 8 blue marbles and 3 black marbles. What is the probability of picking a black marble, replacing it, and then picking a red marble? Answer a. 2/27 b. 7/108 c. 14/81 d. 1/9
Choice A. <span>14/81 </span>Possible outcomes = total number of marbles = 18 P (1st blue) = 8/18 = 4/9 P (2nd red with replacement of blue) = 7/18 P (both) = (4/9) * (7/18) = 28/162 = 14/81
Choice B. 7/18 Possible outcomes = total number of marbles = 18 <span>P (1st black) = 3/18 = 1/6 </span> <span>P (2nd red with replacement of black) = 7/18 </span> <span>P (both) = (1/6) * (7/18) = 7/108</span>
