I need hep with this question can someone help me

Organic apples are on special for $1.50 per pound. does total cost vary inversely or directly with the number of pounds purchased? find the cost of 3.4 pounds of apples. a. inversely: $5.10 b. directly; $5.10 c. inversely: $2.27 d. directly; $2.27

What is the radius of a circle with an area of 78.5 cubic inches? use 3.14 for pie

What is the inverse of the function f(x) = 2x + 1?