Question

Suppose there are three blue marbles and three yellow marbles in a bag and you want to remove two marbles. You do not replace the first marble. What is the probability that you will select a blue marble and then a yellow marble? Express your answer as a percent

Answer 1

Total sample space {b,b,b,y,y,y,} => (3blues +3 yellows) =all possible outcome

P(1st draw =b) =3/6 =1/2= 0.5 or 50%

Since it's not replaced, the sample space becomes {b,b,y,y,y}

P(2nd draw=y) = 3/5 = 0.6 = 60%

Now the probability of drawing a blue AND a yellow (blue ∩yellow), becomes a conditional probability that means P(b∩y) = p(b) x P(y)

P(blue AND yellow) = 0.5 x 0.6 = 0.3