Question

Two similar pipes are shown.



The small pipe has a radius of 18 feet and a height of 21 feet while the large pipe has a height of 28 feet. What is the volume of the large pipe in terms of π?

5,376π ft3

18,432π ft3

6,804π ft3

16,128π ft3

Answer 1

Hint: If the two pipes are similar, then the rations of their radius to height should be the same.

Answer 2

Small pipe: r=18, h=21
Large pipe: H=28

The pipes are similar so\[r/h=R/H\]\[R=Hr/h=28*18/21=24\]
Now just calculate the volume. \[V=H\pi R^2=28(24^2)\pi\]

I don't have a calculator to make sure but I think the answer is D. You will want to use a calculator to make sure.