# #8.99*10^9# seconds is how many years?

##### 1 Answer

#### Explanation:

Your strategy here will be to use a series of **conversion factors** to take you from

secondsto minutes

#"1 minute " = " 60s seconds"#

minutes to hours

#"1 hour " = " 60 minutes"#

hours to days

#"1 day " = " 24 hours"#

days toyears

#"1 year " = " 365.25 days"#

The last conversion factor doesn't use a *whole number* because once every *leap year*, which means that instead of **days**, the number of days we have in a regular year, we get **days**.

So, use the conversion factors to find

#8.99 * 10^9 color(red)(cancel(color(black)("s"))) * (1color(red)(cancel(color(black)("min"))))/(60color(red)(cancel(color(black)("s")))) * (1color(red)(cancel(color(black)("hr"))))/(60color(red)(cancel(color(black)("min")))) * (1 color(red)(cancel(color(black)("day"))))/(24color(red)(cancel(color(black)("hr")))) * "1 year"/(365.25color(red)(cancel(color(black)("days"))))#

#=2.85 * 10^2"years" = "285 years"#

The answer is rounded to three **sig figs**, the number of sig figs you have for