Question

A marble is drawn at random from a bag containing 2 blue marbles, 3 yellow marbles, and 7 orange marbles. What is the probability that the marble is not yellow and not blue?

Answer 1

total marbles: 2+3+7 = 12

add blue and yellow 2+3=5

 7 marbles aren't blue or yellow

probability = 7/12 marble is not one of those