To calculate the minimum and maximum volume of water contained in the ocean, you must calculate the volume in a sphere at the surface of the ocean

To calculate the minimum and maximum volume of water contained in the ocean, you must calculate the volume in a sphere at the surface of the ocean (10km above the core), and then subtract a volume the size of the core. The volume of a sphere = 4⁄3πr3.

Minimum volume (below the 40 km thick crust): 
________________________km3
Maximum volume (below the 30 km thick crust): __________________________km3