In: Statistics and Probability
2. Suppose that a box is known to contain 50 red and 25 blue marbles. Two marbles are to be drawn in succession. The first marble is set aside and its color noted. It is not placed back into the box before the second marble is drawn.
a. Sketch a probability tree which represents this situation.
b. What is the probability that the second marble is red, if the first marble is red?
c. If the second marble is blue, what is the probability that the first marble is red?