Custom Answer For Text Input Question Validation

Hi,

Is it possible to add a custom validation value to correctly assess whether or not someone entered the correct answer on a text input question type?

I see we have these 4 options to validate this question type (Alphanumeric, Numeric, email address, Places).

I want users to do a math problem and then enter in the correct answer but I'm not seeing a way to tell outgrow what the correct answer is.