Suppose you are drinking root beer from a conical paper cup. The cup has a diameter of 6 centimeters and a depth of 7 centimeters. As you suck on the straw, root beer leaves the cup at the rate of 8 cm /sec. At what rate is the level of the root beer in the cup changing when the root beer is 6 centimeters deep? The rate the root beer depth is dropping is (minus) X cm/sec