A bag is filled with 7 black (B) marbles and 3 red marbles (R).

You draw marbles from the bag in pairs.Denote the four possible outcomes of drawing the marbles with the letter pairs BB, BR, RB, and RR.

Compute the probability of the following outcomes.BB:

BR:

RB:

RR:

In each outcome we count the number of black marbles. Compute the probabilities of the following events.

0 Black Marbles:

1 Black Marble

2 Black Marbles:

If we repeat drawing sets of 2 a large number of times and compute the average number of black marbles from each draw, what do we expect that average to be?