If it's choice between doing work for Google and solving those meaningless random ones that that contribute to nothing I'll help Google anyday.

That's a false choice.

The real choice is between doing Captcha work for Google and not doing Captchas.

In this respect, you're welcome.

Strange, I also tried giving a close but wrong answer a few times and it never accepted it.

Of course it lets you through, it can't check that (at that time)

But it doesn't mean you're the only one that got that sample. So they pick the most "popular" answer