Yes, solving previous years question papers of UPSC Mathematics optional subject can help in improving your problem-solving approach. Here are some reasons why:

1. Familiarity with Exam Pattern and Question Types:
- By solving previous years' question papers, you become familiar with the exam pattern and the types of questions asked in the UPSC Mathematics optional subject.
- You can understand the weightage given to different topics and the level of difficulty of questions.
- This familiarity helps you in strategizing your preparation and allocating time to different topics accordingly.

2. Identifying Important Topics:
- Solving previous years' question papers helps you identify the important topics that are frequently asked in the exam.
- You can analyze the trend of questions and focus more on those topics to enhance your preparation.
- It gives you a clear understanding of the areas where you need to work harder and improve your knowledge.

3. Practice and Time Management:
- Solving previous years' question papers provides you with ample practice and helps you improve your problem-solving skills.
- It helps you develop a systematic approach towards solving problems and improves your time management skills.
- By solving a variety of questions, you become more efficient in tackling different types of problems within the given time frame.

4. Understanding the Exam's Expectations:
- UPSC Mathematics optional subject question papers reflect the level of understanding and depth of knowledge expected from the candidates.
- By solving these papers, you get a clear idea of the level of conceptual clarity, analytical skills, and problem-solving abilities that are required to excel in the exam.
- It helps you align your preparation and study methods accordingly to meet the exam's expectations.

5. Boosting Confidence:
- Solving previous years' question papers helps in boosting your confidence level as you become familiar with the exam pattern and gain more practice.
- It gives you a sense of accomplishment when you are able to solve questions correctly, which in turn motivates you to perform better in the actual exam.

Conclusion:
Solving previous years' question papers of UPSC Mathematics optional subject is an effective strategy to enhance your problem-solving approach. It helps in understanding the exam pattern, identifying important topics, improving practice and time management skills, aligning your preparation with the exam's expectations, and boosting your confidence level. By utilizing these papers effectively, you can improve your chances of scoring well in the UPSC Mathematics optional subject exam.