Geometry Word Problem Help?

Question

An office water dispenser holds 18.9 L of water. The paper cones from which people drink are 9.5 cm high with radius 3.5

a) how many full cones of water can be dispensed from the container?

b) what is the minimum amount of paper needed to construct the number of cones in part a?

Answer 1

a) The volume of a right circular cone is:
V = (1/3)πr^2h
V = (/3)π(3.5)^2(9.5)
V = 121.868cm^3
# of cones = (18.9)(1000)/121.868 = 155 cones

b) Lateral surface area of a right circular cone:
A = πrL
Where L is the slant height:
L = √(r^2 + h^2)
Area of paper = (155)π(3.5)√(3.5^2 + 9.5^2) = 17254.86cm^2