Question 566148
Use the formula v= 4/3 pi r^3

1.  If the radius of a ball is twice that of another, how many times as big is its volume?
8 times.
{{{V1 = 4*pi*r^3/3}}}
{{{V2 = 4*pi*(2r)^3/3 = 4*pi*8r^3/2}}}
The volume is related to r^3.  (n*r)^3 = n^3*r^3
Volume is a function of the cube of the radius.

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2.  If the volume is twice that if a blue ball, how many times as big is its radius?
Volume is a function of the cube of the radius.
I don't know about the color, but the radius is {{{root(3,2)}}} times.