The volume of a sphere whose diameter is 18 centimeters is 246 324 648 972 π cubic centimeters. if its diameter were reduced by half, its volume would be 1/2 1/4 1/6 1/8 of its original volume.

Radius of sphere = 18/2 = 9 cm

Volume of sphere = 4/3 πr^3 = 4/3 x π x (9) ^3 = 972 π cubic cm

If the diameter is reduced by half, then

Volume = 4/3 x π x (9/2) ^3 = 4/3 x π x (9) ^3 x (1/2) ^3 = 1/8 (972)

Therefore, new volume is 1/8 of original volume.