Help with some of my homework, please and thank you

Adaycare center charges a $75 enrollment fee plus $100 per week. which of the following represents the cost of sending a child to daycare for 14 weeks?

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

Collin did the work to see if 10 is a solution to the equation r/4=2.4