Question

You have a jar of marbles in front of you 2 are green, 9 are yellow, 3 are white and 7 are red. What is e probability, as a decimal, of selecting a marble that is white or yellow, followed by a marble that is green?

Answer 1

Sample space = 21

Pr(White or Yellow) = Pr(White) + Pr(Yellow)

Pr(White) = 3/21 = 1/7

Pr(Yellow) = 9/21 = 3/7

Therefore,

Pr(White or Yellow)= 1/7 + 3/7 = 4/7