We have a box with six green marbles, five blue marbles, and seven red marbles. We choose three marbles from the box at random without looking. What is the probability that none of them will be blue?
A)0.38
B)0.29
C)0.45
D)0.35

Question

Quizplus · Accepted Answer

The total number of marbles is 6 green + 5 blue + 7 red = 18 marbles. The probability of choosing three marbles that are not blue involves choosing only from the 6 green and 7 red marbles, which totals 13 marbles. The number of ways to choose 3 marbles from these 13 is calculated using combinations: C(13,3) = 13! / [3!(13-3)!] = 286. The total number of ways to choose any 3 marbles from the 18 is C(18,3) = 18! / [3!(18-3)!] = 816. Therefore, the probability is 286 / 816 = 0.35.

We Have a Box with Six Green Marbles, Five Blue