What tier are you using? I have run lots of problems and am very impressed, but I find stupid errors a lot more frequently than that, e.g., arithmetic errors buried in a derivation or a bad definition, say 1/15 times. I would love to get zero failures out of thousands of (what sounds like college-level math) posed problems.

I have a standard OpenAI/ChatGPT Pro account; GPT5 is my daily driver for math, and Claude for code.