this post was never a "memorize this and you will know scala" statement, or that if you know those answers you will get a scala job. I simply found those questions a while ago and decided to provide answers by myself as an exercise. I do believe some answers may not be completely right (even completely wrong), and others may be a starter for a nice and productive discussion.
Also, knowing the answer to these questions doesn't make someone a good/better developer. These are just some small islands on the (scala) software developer knowledge!
In my opinion these are somehow basic concepts (that will only be valuable when applicable on 'real life' code), and there is a lot more to explore, specially about the type system. To know more about the type system have a look at this awesome article I found: http://ktoso.github.io/scala-types-of-types/
Unfortunately, these are questions often done in several scala-related job interviews (I had my share. Coincidence or not, I never accepted an offer from a company which did that kind of questions) :(
Feel free to provide feedback or discuss some topics.