These examples do a lot more - and so are hard to read...

[gordonwatts]

These examples do more than they are required to do. For example, example 1 is not only making the MET histogram, it is filling a cut-flow table, and it looks like it is being designed to run as a processor so it can run distributed.

The point of the main 8 challenges is to show case the actual work on the data query part of the code. Adding the cutflow, or running distributed, etc., perhaps could be a different set of challenges - and these ones could be simplified.