Question

A bag contains 6 red marbles, 2 blue marbles, and 1 green marble. What is the

probability of choosing 2 marbles that are not green when 2 marbles are drawn
from the bag? (no replacement before choosing second marble)

Answer 1

We have 1 green and 8 non-green.

We get a probability of 8/9 of a non-green for the first marble and a probably of 7/8 for the second being non green, so

p = (8/9)*(7/8) = 7/9

Answer: 7/9