The answer to this is that there are 45 minutes in 2700 seconds.
As I imagine that you know, there are 60 seconds in every minute. Because of that, you can find how many minutes make up a given number of seconds by dividing. When you divide 2700 seconds by 60, you come up with 45. That is the answer in minutes.
You can set this up mathematically by saying
2700 S = X M (S = seconds, M = minutes).
You know that M = 60s.
So now you can write the equation as
2700S = x*60
Now divide both sides by 60 and you get 45.