Approximately how many segments did the whole earthworm have?

Between 120 and 170.

Explanation:

Earthworm belongs to membrane of phylum Annelida. Membrane of this phylum shows the bilateral symmetry, containing a rudimentary head region, and have segmented bodies.

An adult earthworm has approximately more than 120-170 segments on their bodies, which is known as annuli. They are hermaphrodites in nature each having male, and female sex organs. They lack a true skeletal, and maintain their body with fluid-filled coelom chamber which function as a hydrostatic skeletal.