Simple problems resolved

Good morning!

I added the files with the solutions.
They were created in Visual Studio 2010.

Here is a print screen of the VS Solution if you want to reproduce it:
![vs_solution](https://cloud.githubusercontent.com/assets/8064846/3478786/0748603c-0344-11e4-9cd8-14a79bd121ac.png)

The UnitTests project needs a reference to the SimpleProblems project.

Thank you for your time.
@pirvudoru 
I see this is also an extension method, used together with the IsEven() method.
Now every array can calculate it's own sum of even numbers.

Lots of wasted code has been removed. Good solution.

@everyone
I learned lots of good things today so thanks everyone for sharing your thoughts.