A 15 year old who has just turned 15 years old has lived for 5,475 days.

That is assuming the 15 year old is just 15 and not 15 and some days.

Since there are 365 days in a year the 15 year old has lived 365 days each year of their life.

In a week there are 168 hours.

In a day there are 24 hours and in a week there are 7 days so to get the amount of hours in a week we take the 24 hours and multiply it by 7 which gives us 168.

So that means there's 168 hours in a weeks time.

In every minute there are 60 seconds and there are 60 minutes in every hour which means there are 3,600 seconds in an hour.

1 hour = 60 minutes and 1 minute = 60 seconds so 60 minutes/ hour * 60 seconds/ minute = 3600 seconds/ hour or 1 hour = 3600 seconds.

In 2 days there are 172,800 seconds.

In a day there are 86,400 seconds.

We also know there are 24 hours in one day. If we multiply all of those, we end up with 86,400 seconds in 1 day.

In a day or in one day there are 1,440 minutes and in a day there are also 24 hours.

In 12 years there are 378,432,000 seconds.

The conversion of 12 years to seconds is calculated by multiplying 12 years by 31,536,000 and the result is 378,432,000 seconds.

In a year of 365 days there are 31,536,000 seconds.

1 year, 12 months, 365 days, 8760 hours, 525,600 minutes, 31,536,000 seconds.

That seems like a lot of time but that time goes by really quick.

In a year there are 12 months.

There are also 365 days in a year and always 12 months in each year.

In 10 years there are 120 months and 3,650 days.

In 5 years there are 60 months and 1,825 days.

And in a year there are 525,600 minutes.

Also it is easiest to determine and work with the total number of days in a year, which is 365.

To arrive at the answer, all you need to do is to multiply the number of minutes in a single hour with the total number of hours in a day.

i.e. 1440 (minutes) x 365 = 525,600 minutes (in a year).

On Earth, a solar day is around 24 hours. However, Earth's orbit is elliptical, meaning it's not a perfect circle.

That means some solar days on Earth are a few minutes longer than 24 hours and some are a few minutes shorter.

On Earth, a sidereal day is almost exactly 23 hours and 56 minutes.

There would be approximately 52560000 minutes in hundred years and 40471200 minutes in 77 years.

1 min =60 sec. 1 Day=1440 min.