Yes, math is confusing for me actually. But then again, I take comfort in knowing it was so with Einstein too.
Actually, this is a hugely untrue rumor. Einstein was a BRILLIANT mathematician.
Either way, you didn't save 100%. You saved 100% of the cost of air by not going EANx. A percentage is simply a represntation of how much of something you're referring to. 100% of your air fill costs is exactly the same as 50% of your nitrox fills. It's not a math thing, it's a logic thing. You have to say percent OF something. It would have cost you an additional 100% OF the cost of your air fills to go EANx. It would have cost 200% the cost OF your air fills to go Nitrox. By going air, you paid 50% of the cost of EANx. Does that all make sense?
Either way, your "third group" of divers is where I think a lot of divers are at. I'm not mix-certified, but I'll dive to 130ft on air without a second thought in clear blue waters. I would rather not be at 130ft in a cave I'm unfamiliar with without a buddy. I'd also not want to get deep in a really dark water. I wouldn't mind going deeper than 130ft in clear water, but I'd definitely draw the line at 187ft (1.4PO2). If I ever decide to get mix-certified, I'll probably start adding trimix on dives starting at 150ft (depending on the location) or anything deeper than 100ft in a physical overhead. If I get rich, I'll take He on my 30ft reef dives. 40/60 mix anyone??
Pavao, the correct word is "worse." Worst means the worst (there are no others that are worse). It's a noun, as in: it's the WORST pie I've ever eaten. Worse is a comparative word: "This pie is worse than that one." They could both be really good, but if one is bettet....the other is worse. If you've never had a worse pie, it would be the worst pie. Worst and Best are opposites, and so are More and Better. Pavao sounds portuguese, and I don't speak it well....but in spanish, worst is "el peor" and worse is "peor" and I believe portuguese to be the same way. I hope that helps. It's really confusing, until you think about using "the" with the words ("the worst" and "the best" vs "worse" and "better").
---------- Post added February 28th, 2014 at 01:47 PM ----------
It always amazes me how often the point of a post can become obfuscated by the minutia of the math.
It sounds like someone did well on their SATs

. (Oh, you Canadians probably don't have those. Well, on standardized tests that test random vocabulary words.)