Too many languages. Cut it down to 2 at most: 1 for learning the logic and basics, 1 for actually making a project.
If your goal is just to get someone to minimum competence so they can build something, it's better to stick with one language (or, at worst, just a web stack), at the very least so they don't get bogged down installing a bunch of tools for relatively little benefit. PHP and Ruby are both Algol derivatives, so having a person solve Project Euler problems in both and compare them won't likely reveal much more than trivial differences.
Also, unless they have a decent math background, 100 Project Euler problems is just going to frustrate and scare off people - some of those problems are pretty much intractable without Dynamic Programming; anyone who hasn't taken an algorithms course would probably take a long time to figure that out.