how does this gauge dev's capability to work on .NET Web app ?

Curious to know - how would the following piece of code gauge my ability to code a .NET API project. This is a genuine question. I did not know the answer, took me a minute after the interview.

There was an error on the third line. Not sure if it was my IDE. Anywho any ideas.

byte foo = 100; 
dynamic blue = foo;
Console.WriteLine(Type.GetType(blue));
blue += 100;
Console.WriteLine(Type.GetType(blue));
Console.ReadKey();