If you double the radius of a sphere, its volume increases by what factor?

Question

A. 8
B. 6
C. 2
D. 4
I thought maybe C.2 or D.4

Answer 1

V = (4/3)(pi)(r)^3

V = (4/3)(pi)(2r)^3
V = (4/3)(pi)8r^3

(4/3)(pi)(8)(r)^3 ÷ (4/3)(pi)(r)^3

Everything cancels out but the 8, so the answer is A.