This way if people feel motivated at cheating at captcha they will end up
helping Wikipedia It is up to us to try to balance things out.
I'm pretty sure users will be less annoyed at solving captchas that
actually contribute some value.
Obligatory XKCD: https://xkcd.com/810/
The best CAPTCHAs are the kind that do this. Look at how hard it is to beat reCAPTCHA because they have taken this approach. One must be careful though that the CAPTCHA is constructed such that it won't be as simple as a lookup though, and will actually require some thought (so that probably eliminates the noun, verb, adjective idea).
This idea has my support.
Thank you, Derric Atzrott