Question

How many grandparents have my grandparents?

Answer 1

This doesn't have enough information. it spend on ages, how many children per generation, if direct bloodlines only or adoption count, half relatives, etc.

Answer 2

Answer: Well, each grandparent would only have two parents, and those parents would each have two parents, unless adoption was involved, so there would be four grandparents for each grandparent. Eight would be your answer, I think.