What is the volume of the tank? Round answer to nearest cubic foot?

Question

A propane tank is made up of a cylinder with hemispheres
on each end. If the total length of the tank is 6 feet and
height is 2 feet,what is the volume of the tank? Round
answer to nearest cubic foot?

I don't know what they mean by 'height' here. I think they mean the tank is lying on its side, so 2 ft would be the diameter of each hemisphere, and the diameter of the cylinder.

That makes the radius 1 ft.
a sphere with a radius of 1 foot.

Volume of a cylinder = 3.14 x r^2 x height
=3.14 x radius x radius x height

Volume of a sphere = 4/3 x 3.14 x radius^3
= 4/3x 3.14 x radius x radius x radius

Volume of a hemisphere =4/3 x 3.14 x radius x radius x radius x 1 /2

2 Hemispheres makes one sphere
Volume of composite solid=Volume of a cylinder + Volume of a sphere

(3.14 x 1 x1 x 6 ) + (4/3 x 3.14 x 1 x 1 x 1) =
18.84 + 4.18666666 =23.02666666
Round answer to nearest cubic foot? answer is 23
volume of cylinder is 3.14x1x1x6=18.84 or 3.14x1x1x4 = 12.56?

Answer 1

Good work. But the total length of the tank is 6 feet including the hemispherical ends. So the cylindrical part is:
3.14x1x1x4 = 12.56
Plus the hemispherical ends:
(4/3)x3.14x1x1x1 = 4.18
Total:
12.56 + 4.18 = 16.74 cubic feet
Rounded:
17cubic feet