Question

A jar contains 9 red marbles, 7 green marbles, and 5 blue marbles. 34. If a single marble is drawn from the bag, what is the probability that it is red? (3 pts) 35. If three marbles are drawn without replacement, what is the probability that all three Subles are green? [4 pts) 36. I samarbles are drawn with replacement, what is the probability that at least 1 blue marble was selected. 5 pts

Answer 1

34)If a single ball is drawn ,the probability that it is red=$\frac{^9C_1}{^{9+7+5}C_1}=\frac{^9C_1}{^{21}C_1}=\frac9{21}=\frac37$

35)If three balls are drawn at random without replacement,the probability that all three are green=$\frac{^7C_3}{^{9+7+5}C_3}=\frac{^7C_3}{^{21}C_3}=\frac1{38}$

36)If six balls are drawn at random with replacement, the probability that all at least one blue ball was selected =$1- \frac{5^{6}}{21^{6}}$