Question

Ernie is making a cylinder-shaped container to store his pens. The container has a base on one end and an opening on the other end. He is going to spray paint the outside of the container. The container has a diameter of 3 inches and a height of 18 inches.

Answer 1

For this case we must calculate the surface area of the container to know the amount of paint that Ernie must use.
 We have then:
 A = pi * r ^ 2 + 2 * pi * r * h
 Where,
 r: cylinder radius
 h: cylinder height
 Substituting values:
 A = 3.14 * (3/2) ^ 2 + 2 * 3.14 * (3/2) * 18
 A = 176.625 in ^ 2
 Answer:
 The amount of paint needed is:
 A = 176.625 in ^ 2