Question

Guess me : Twice ten are six of us, Six are but three of us, Nine are but four of us; What can we possibly be?.......... Twice ten are six of us, Six are but three of us, Nine are but four of us; What can we possibly be? Would you know more of us? Twelve are but six of us, Five are but four, do you see? What are we?

Answer 1

It is the "NUMBER OF LETTERS IN EACH NUMBER"

twice of ten = twenty (6 letters)
six (three letters)
nine(four letters)

Answer 2

The numbers of letter in each number is the ans