title: Given a time complexity, how do you calculate run time given an n?
body: <p>I was given an algorithm and estimated the time complexity T(n) to be 3*n! + 2.</p>
  
  <p>I know that the time required for the algorithm to run when n = 10 is 1 second, and I wish to calculate the run time for n = 20. </p>
  
  <p>I'm a little confused on how to approach this. I assumed since n=10 that I just plug it into T(n), which gives 3*(10!) + 2, which is obviously not 1 (second). </p>
  
  <p>Can anyone give some tips on how to approach this properly? Thanks!</p>