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?

Let diameter = de and radius = de/2
Diameter of moon = de/4 and radius = de/8
Vol of moon = (4/3)πr³ = (4/3)π(de/8)³
Vol of earth = (4/3)π(de/2)³
Ratio = Vol of the Moon / Vol of the Earth = [(4/3)π(de/8)³] / [(4/3)π(de/2)³] = Vol of Moon / Vol of Earth = 1/64
Volume of moon = (1/64) Volume of earth