The radius of the base of a right circular cone is 4 in., and its slant height is 15 in. If the radius and the slant height are each multiplied by 6, by what factor is the surface area multiplied? A. 6 B. 9 C. 12 D. 36

Step-by-step explanation:

radius r = 4 in

slant height L = 15 in

base area = πr² = 16π in²

lateral area = πrL = 60π  in²

surface area = 76π in²

r = 4×6, L = 15×6

base area = (4×6)²π = 16π×36

lateral area = 60π×36

surface area is multiplied by 36