title: Calculating the amount of time an algorithm takes to run given a certain input size
body: <p>I'm revising for an exam entitled "Algorithms and Scientific Computing" and have little idea about how to do this question, it's from a past exam paper. I know an algorithm with O(3^n) complexity triples in complexity with each new element added and an algorithm with O(n^3) complexity grows proportional to the cube of n, but I don't know how to use that information to answer the question. Here is the question, I would hugely appreciate any help given. Thanks.</p>
  
  <p><strong>Algorithms A1 and A2 are stated to have complexities On^3and O3^nrespectively. On an input of size n = 10,000 both algorithms run in exactly the same time t = 10 seconds. How much time do you expect each algorithm to take on an input of size
  i. n = 9,990 ii. n = 30,000</strong> </p>