SOLUTION: a bag contains 8 red marbles, 7 blue marbles, and 5 green marble. Two marbles are randomly selected from the bag, what is the probability that both are NOT blue?

Algebra ->  Probability-and-statistics -> SOLUTION: a bag contains 8 red marbles, 7 blue marbles, and 5 green marble. Two marbles are randomly selected from the bag, what is the probability that both are NOT blue?      Log On


   

Question 843356: a bag contains 8 red marbles, 7 blue marbles, and 5 green marble. Two marbles are randomly selected from the bag, what is the probability that both are NOT blue?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Let's find the probability that both are blue since P(both blue)+P(both not blue)=1.
I'm assuming it's without replacement.
P%281B%29=7%2F%288%2B7%2B5%29=7%2F20
and the second,
P%282B%29=6%2F19
So then
P%28B%2CB%29=%287%2F20%29%286%2F19%29=%287%2F10%29%283%2F19%29=21%2F190
So then the probability we want is,
P=1-21%2F190=190%2F190-21%2F190=169%2F190