[agf]

I appreciate the lesson trying to be taught here -- don't be intimidated by what you don't know, develop a plan, and practice -- but I don't think the author chose good examples.

For the LCM example, the second solution doesn't show any understanding of the underlying problem. The point of project Euler is to think about algorithms -- not to take advantage of "batteries included" features of programming language standard libraries.

For the duplicate counting problem, while the second answer is shorter, it's a bad solution. Just a few of the problems: it calls `split` many times instead of once; `count` can be called directly on a string; `chars` is the right way to get the characters of a string in Ruby; and finally the problem can be solved in 1-2 passes over the data using something like Ruby's `Enumerable#group_by` or Python's `itertools.groupby` rather than in a number of passes proportional to the length of the data -- O(n) rather than O(n^2).