I need help please someone ps. sorry if u can barely read the question. you have to find out what that black thing is

At a sand and gravel plant, sand is falling off a conveyor and onto a conical pile at a rate of 16 cubic feet per minute. the diameter of the base of the cone is approximately three times the altitude. at what rate is the height of the pile changing when the pile is 12 feet high? (hint: the formula for the volume of a cone is v = 1 3 πr2h.)

What is the sum of these mixed numbers 2 1/8 + 4 3/8

An air conditioning system can circulate 350 cubic feet of air per minute. how many cubic yards of air can it circulate per minute?