Jake has two similar cylindrical pipes. The radius of the first cylindrical pipe is 5 cm. The circumference of the second cylindrical pipe is 20π cm.

Question

The volume of the second cylindrical pipe is how many times greater than the volume of the first cylindrical pipe?

A.3
B.4
C.5
D.8

Answer 1

since C=2pi*r, the radius of the 2nd pipe is 20π/2π = 10

so, the 2nd pipe has radius twice the 1st pipe.

If linear dimensions scale by n,
area scales by n^2
volume scales by n^3

So, now you have what you need.