Seems like you want to assume that if someone's first language is not english, or they're bad at math, that they're a bot?
Or, if this is a real person who just happens to not be there at the keyboard when they join the channel. For example, I "prove" that I'm not a bot, but later something disconnects me while I'm away. My mirc rejoins the channel while I'm not there, and since I'm not at the keyboard, this "proves" that I am not a bot.
If your real goal is to keep bad behaving nicks out of the channel, another way is to require people be identified to nickserv before they join the channel. Most automated bot scripts are not identified, and if someone does manage to register one of them, that gives a target to be banned.