RxJS author here and creator of some of those exercises. This was meant as a hands on lab where we proctor the event. We've given this at a number of conferences including QCon, CodeMesh, among others to great success. If you have suggestions, please do file an issue and I'll make sure we get them addressed: https://github.com/jhusain/learnrx
It was design for IRL teaching. That said, if you know FP already and want to see what they say about it, it's annoying to go through the steps manually. Time to hack the class I guess. Functionally.
I wanted to read it, then noticed most of the page as blank space, shrugged, and moved on.