Complexity and Execution time

Suppose a C++4.8.1 program is O(N) and N=10000, then how much time (in seconds) will it approximately take to run?

Unless your constant is too large (greater than 100 or more) it should run in a few milliseconds show an execution time of 0.00 on codechef.While designing your algorithm, You can assume that roughly 10^8 computations can be done in a second.