[seebs]

I think the 5th one is harder because it has a lot of reliance on recognizing a specific syntax for key/value stores, and may rely on realizing that a key/value store can have another key/value store as one of its values. This code couldn't be written recognizably-the-same in at least a couple of the languages I use which have key/value stores, and would be syntactically quite different in some. If you don't recognize the syntax, you have to start thinking about the problem and ruling things in or out, and that's harder. Probably still possible, but it's going to be testing at least some amount of a test-taking skill that isn't always taught.