Doesn't make sense? Let me explain.
A captcha are those weird words the internet asks you to type in to verify that it is actually a human using the computer, and not some robot. You know, those funky pictures that are all swirly and ask you to type some letters in... popular examples is if your signing up for something, buying something off the internet, watching adult videos. You know, common stuff.
They look like this...
Now that you know what they are... look at the captcha I got the other day on Facebook.
How are you going to make me type a calculus problem as a captcha? How are you going to make me use a TI-89 Titanium graphing calculator to post something on my Facebook? Am I going to need a number 2 pencil and paper to do this?
Seriously though, how do expect me to do that fraction? Of course if I wanted to take the time to try and figure this out, I would have got it easy. But, c'mon... just to post on my Facebook? Really?