General Mental Ability Syllabus 

• Blood Relations
• Setting Arrangement
• Data Interpretation
• Direction and Arithmetic Questions
• Puzzles
• Data Sufficiency 
• Syllogism
• Calendar
• Clock
• Statement and Conclusion ETC.

While there isn't one specific book designed solely for the UPSC EPFO exam's General Mental Ability section, there are a couple of resources that can be quite helpful for your preparation. Here are two recommendations:

Tata McGraw Hill

Verbal and Non-Verbal reasoning by R.S. Agarwal

Here's a strategy to tackle the General Mental Ability (GMA) section of the UPSC EPFO exam:

Understand the Syllabus:

Begin by familiarizing yourself with the specific topics covered in the UPSC EPFO GMA section. This will help you focus your preparation efforts. Resources like previous years' papers and official notifications from UPSC can provide this information.
Strengthen Core Concepts:

The UPSC EPFO GMA section typically covers areas like reasoning, analogy, coding-decoding, number series, and basic mathematics. Brush up on the fundamentals of these areas. There are many resources available online and in bookstores to help with this.
Practice with Previous Years' Papers:

Practicing with previous years' question papers is crucial. This exposes you to the question format, difficulty level, and types of questions asked in the exam. You'll also develop a sense of time management, which is vital in the actual exam.
Focus on Speed and Accuracy:

The GMA section is often time-bound. Aim to solve questions quickly and accurately. Develop techniques like approximation and elimination to save time.
Mock Tests and Analysis:

Take mock tests regularly to simulate the exam environment and identify your weak areas. Analyze your performance after each test and work on improving your weaker topics.
Develop Test-Taking Strategies:

Learn time management skills to allocate time effectively during the exam. There's no penalty for negative marking, so avoid spending too much time on a single question. If you're stuck, move on and come back later if time permits.
Additional Tips:

Develop a good reading habit to improve your comprehension skills, which are essential for solving many GMA questions.
Stay calm and focused during the exam. Don't get intimidated by difficult-looking questions.
There are online resources and coaching centers specifically dedicated to UPSC EPFO preparation. Explore these options if you need additional guidance.
By following these strategies and practicing diligently, you can significantly improve your chances of scoring well in the UPSC EPFO GMA section.