We know that 1 year = 365.25 days
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
=> 1 Year = 365.25 x 24 x 60 x 60 Seconds
But 1 billion seconds = ?
1 Year = 365.25 x 24 x 60 x 60 Seconds
? = 1000000000 Seconds
? = 1000000000365.25 x 24 x 60 x 60 years">? = 1000000000365.25 x 24 x 60 x 60 years
= 31. 68 years