Matt picks a marble from a bag, replaces it and then chooses a second marble. There are 3 red marbles in the bag and 2 black marbles. Draw
a tree diagram showing the possible outcomes for Matt's marbles. What is
P (red marble on both turns)?

Gravel is being dumped from a conveyor belt at a rate of 25 ft3/min, and its coarseness is such that it forms a pile in the shape of a cone whose base diameter and height are always equal. how fast is the height of the pile increasing when the pile is 14 ft high? (round your answer to two decimal places.) ft/min