Final answer:
The fee for retaking a knowledge test after failing two or more times varies by location and testing authority, and official sources should be consulted for specific amounts.
Step-by-step explanation:
The fee to retake the knowledge test after failing two or more times can vary depending on the state or country you are in, as well as the specific testing authority. These organizations often have a set fee for retaking tests which is intended to cover administrative costs. For an accurate fee amount, you would need to consult the website or contact the customer service of the DMV, MVA, or equivalent authority administering the test. As general guidance, some testing authorities might charge a standard retesting fee for each additional attempt, while others increase the fee after multiple failures to dissuade repeated attempts without further study.