A generation is about one-third of a lifetime. Approximately how many generations have passed since the year 0 AD?

To answer this question, we need to make a few assumptions.

1. First, we need to determine the length of a lifetime. For simplicity, let's assume an average lifetime is about 75 years.

2. Next, we need to determine the length of a generation. If a generation is about one-third of a lifetime, then a generation would be approximately 25 years (75 years / 3).

3. Now, we need to determine how many years have passed since the year 0 AD. As of 2022, it's been about 2022 years.

4. Finally, we divide the total number of years by the length of a generation to find the number of generations. So, 2022 years / 25 years/generation = approximately 80.88 generations.

Therefore, approximately 81 generations have passed since the year 0 AD.