how is scrum velocity calculated code example

Example: velocity in scrum

Velocity is one of the planning
tool used to estimate the speed of the work
and time of completion of the project.
• The calculation of velocity is
done by reviewing the work team has
successfully completed during
earlier sprints;
• for example, if the team completed 
5 stories during a two-week sprint and
each story was worth 3 story points, 
then the team's velocity is 15 story
points per sprint.