Yeah, the 180million number is irrelevant. What's important is the number and variety of patterns, not the number of questions. I don't even need to program so

Yeah, the 180million number is irrelevant. What's important is the number and variety of patterns, not the number of questions. I don't even need to program something which will understand all of the patterns. I just need to program something that will understand some of the patterns, which just keeps fetching captchas until it eventually understands the format, eg "What is X plus Y?" This captcha system is considerably more simple to break than the typical image based ones.