Because Linq is functional magic. And it does not allow you to feel the solution to the problem for real.

Linq is not the answer to everything, that's correct. But it is the right tool for this task.
Why writing a lot of complicated and hard-readable code, when a simple and easy-to-read Linq-Query does exactly, what you want?
For the readability; write only one Linq-command per line and it's super readable.

This is a only math solution!!!

Linq is not always the answer to everything... Although from most of the top ranked answers I have seen on this site for C# so far it seems to be! It seems all the "highest Best practices" have a magic linq one liner. Hardly readable in some cases.

• Update the code to use "bool" instead of "Boolean"
• Remove the Console.WriteLine() in one of the final test cases.