Sand falls off of a conveyor belt at a rate of 3 in3/sec . If the sand forms a conical pile in which the height of the pile is always equal to twice the radius, at what rate is the height of the pile changing when the volume of the pile is 60 in3 ?

Ahealth-food producer has 250 samples of a new snack to distribute in the mall. the producer has to keep at least 50 samples for display in the health food for the product launch. how long will the samples last if consumers are taking the samples at a rate of 25 every hour