The radius of a basketball is about 3.6 times greater than the radius of a tennis ball how many times greater is the volume of a basketball than a volume of a tennis ball

Volume of a sphere is 
Vbask=4/3 pi (rₐ)^3       where rₐ is the radius of a basketball
v tenn= 4/3 pi (rₓ)^3       where rₓ is the radius of the tennis ball
we know that rₐ=3.6 rₓ

vbasket/v tennis= 4/3pi (3.6 rₓ)^3= we see all is cancelled beside           
                                4/3 pi rₓ
3.6^3=46.65                 
the volume of the basketball is aprox 46.65 bigger than the volume of the tennis ball

Heptagon is the correct ans