Yes, a crash course can cover all the subjects and topics of the NDA exam syllabus. A crash course is designed to provide intensive and focused preparation for the exam within a short period of time. Here is how a crash course can cover each subject and topic of the NDA exam syllabus:

1. Mathematics:
- The crash course will cover all the mathematical concepts and formulas required for the NDA exam.
- It will provide comprehensive practice exercises and mock tests to strengthen problem-solving skills.
- It will focus on important topics such as algebra, trigonometry, geometry, calculus, etc.
- The crash course will provide shortcuts and strategies to solve mathematical problems quickly and accurately.

2. General Ability Test (GAT):
- The crash course will cover all the topics of the GAT section, including English, General Knowledge, and Science.
- It will provide grammar rules and practice exercises to improve English language skills.
- It will cover a wide range of general knowledge topics, including history, geography, current affairs, etc.
- The crash course will also provide in-depth coverage of science topics such as physics, chemistry, biology, etc.

3. Physical Training:
- The crash course will include physical training sessions to help candidates improve their fitness levels.
- It will focus on exercises and activities that are part of the NDA physical test, such as running, push-ups, sit-ups, etc.
- The crash course will provide guidance on maintaining a healthy lifestyle and diet to prepare for the physical test.

4. SSB Interview:
- The crash course will provide guidance on the SSB interview process and the various stages involved.
- It will cover topics such as personal interview, group discussion, psychological tests, etc.
- The crash course will provide tips and strategies to improve communication skills and develop a confident personality.

In conclusion, a crash course can cover all the subjects and topics of the NDA exam syllabus by providing comprehensive study material, practice exercises, mock tests, and guidance on various aspects of the exam. It will focus on strengthening the candidate's knowledge, problem-solving skills, physical fitness, and overall personality development.