Question

A generation is about one-third of a lifetime. approximately how many generations have passed during the last 2,000 years?

Answer 1

Life expectancy is about 75 years.
One third:
75 : 3 = 25
So one generation is about 25 years.
2,000 : 25 = 80
Answer:
Approximately 80 generations have passed during the last 2,000 years.

Answer 2

A generation is defined as all of the people who were born and living during the same time period.  The average length of time most people live is 75 years, to solve how many generations have passed during this time you can divide the length of time by the length of years in question. Though, lifetimes very so it is hard to get an exact amount of generations that have past over time.