Suppose you choose two marbles from a bag containing 2 red marbles, 5 white marbles, and 3 blue marbles. Find the probability that both marbles are blue. find p(red than blue)
1) P(1st marble blue) =3/10 After 2 blue marbles and 9 marbles altogether left. P(2nd marble blue) =2/9. P(both marbles blue) = 3/10*2/9=2/30
2) P(1st marble is red) = 2/10=1/5 Now, we have 3 blue marbles and 9 marbles altogether. P(2nd marble is blue) = 3/9=1/3 P(red then blue)= 1/5*1/3=1/15
