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