The diameter of the moon is approximately one-fourth of the diameter of the earth. What fraction of the volume of the earth is the volume of the moon?

Explanation

Let `d1 and d2` be the diameters of the moon and the earth respectively.
`d1=1/4d2`
`r1r2=1/4`
Volume of sphere`=4/3pir^3`
volume of moon/volume of earth`=(4/3pir1^3)/(4/3pir2^3)=((r1)/(r2))^3`
`((1/4r2)/(r2))^3=(1/4)^3=1/64`