60 sec = 1 minute 60 min = 1 hour 24 hr = 1 day 365 days = 1 year
So, a 35-year old person is roughly 365(35) days old, or 12775 days. Continuing applying conversion factors until you've calculated how many seconds that is. The next calculation is 12775 days times (24 hours) / (1 day)
