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)

2r + 5w + 3b = 10 - marbles altogether.

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