Math quiz! Please help.

Determine the volume of a cylinder bucket if the diameter is 8.5 in. and the height is 11.5 in.

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online