There are 60 seconds in a minute, 60 minutes in an hour, 24 hours in a day, 365 days in a year, for 2012 years. Multiply all those numbers to convert from 2012 years to seconds and you get 63,450,432,000 seconds.
There were 13880 days, including 10 days in leap years from 1975 to 2012. That makes 1,199,232,000 seconds. However, during this period there were 21 leap seconds, so the correct answer is 1,199,232,021 seconds.
There are 1263141040 seconds in 40 years
18 years is about 568,036,800 seconds.
52 years = about 1,640,995,200 seconds.
63,072,000 seconds is about two years.
757,382,400 seconds are in 24 years.
7.5 years is about 236,682,000 seconds.
17 years = 536,467,742 seconds
30 years = 946,707,779 seconds.
70 years is about 2,209,032,000 seconds.
16 years = 504,910,816 seconds.
800,000,000,000 seconds = 25,351.0117 years.