To help with your query about an exam with a maximum score of 20, I’ll need to confirm the specific exam you have in mind, since several tests use different scoring scales. Here are two common examples and how their maximum scores relate to 20:

• GRE: The general test uses a total score of up to 340 (170 per section), not 20. Some subject-area tests use a 200–900 scale, also not 20. If you’re thinking of a test with a 20-point scale, this doesn’t match GRE formats. If you meant a smaller subscore or scaled component that maps to 20, please specify which section you’re referring to.
• Other exams (e.g., certain math or language proficiency assessments in specific countries) may report scaled scores with a maximum of 20. If you can name the country or exam body (e.g., national university entrance exams, high school finals, or professional certification tests), the exact max score can be confirmed.

If you can provide:

• The country or institution administering the exam, and
• Whether you’re asking about the overall maximum score or a particular subscore,

then I can give a precise answer tailored to that exam and explain how a score of 20 would fit within its scoring system.