Yes, you can use chapter notes to prepare for Class 11 Commerce competitive exams like NTSE or Olympiads. Here's how:

1. Comprehensive Review: Chapter notes provide a concise summary of the main concepts, formulas, and theories covered in each chapter. They serve as a quick revision tool to help you review the entire syllabus efficiently.

2. Quick Reference: During the exam preparation phase, time is crucial. Chapter notes allow you to quickly refer to important points, saving you time and helping you focus on specific topics that require more attention.

3. Understanding the Structure: Chapter notes usually present information in a structured manner, highlighting key concepts and their interconnections. This helps you understand the logical flow of the subject, making it easier to grasp complex topics and their relevance to the overall syllabus.

4. Memorization Aid: The concise format of chapter notes makes them particularly useful for memorization purposes. They condense the information into essential points, making it easier to remember and recall during the exams.

5. Focus on Key Points: Chapter notes often emphasize the most important concepts, formulas, and theories. By studying these notes, you can prioritize your preparation and focus on the key points that are more likely to be tested in competitive exams.

6. Revision Tool: As the exams approach, revision becomes crucial. Chapter notes provide a handy revision tool, allowing you to quickly refresh your memory on important topics without having to go through the entire textbook.

7. Supplement to Textbooks: Chapter notes should not replace textbooks or other study materials but should be used as a supplement. They provide a condensed version of the content, helping you to reinforce your understanding and improve retention.

In conclusion, chapter notes are an effective study aid for Class 11 Commerce competitive exams like NTSE or Olympiads. They provide a comprehensive review, serve as a quick reference tool, help in understanding the subject structure, aid in memorization, focus on key points, serve as a revision tool, and supplement the main textbooks. By using chapter notes in conjunction with other study materials, you can enhance your exam preparation and improve your chances of success.