How should i do this? me and tell me the answer

Which of the following is the missing term, a2, of the geometric sequence in which a1=2 and a3=200

Can you simplify 4/7? 24 points will be awarded!

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