• Average 
• Ratio & Proportion
• Number Systems
• Percentage
• Profit & Loss
• Time & Work
• Quadratic Equation
• Compound and Simple Intrest
• HCF & LCM 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:

Quantitative Aptitude by R.S. Aggarwal:This comprehensive book covers a wide range of topics that you'll encounter in the General Mental Ability section of the UPSC EPFO exam, including reasoning, problem-solving, and data interpretation

A Modern Approach to Logical Reasoning by R.S. Aggarwal:This book delves specifically into logical reasoning, a crucial component of the General Mental Ability section. It provides ample practice questions to help you hone your skills.

Remember, consistency is key when preparing for any competitive exam. Set aside dedicated study time each day and practice regularly using these books or other resources you find helpful.

Here's a strategy to tackle Quantitative Aptitude in the UPSC EPFO exam:

Understand the Syllabus and Exam Pattern:

Begin by thoroughly reviewing the official UPSC EPFO syllabus to identify the specific topics covered in Quantitative Aptitude.
Look for previous years' question papers to understand the weightage assigned to different topics and the difficulty level of the questions.
Focus on Core Concepts:

Don't try to master everything. Focus on core concepts like Number Systems, Percentages, Ratio & Proportion, Averages, Simple & Compound Interest, Profit & Loss, Time & Work, Time & Distance, Mensuration, Algebra, and Trigonometry.
Develop Calculation Speed and Accuracy:

Quantitative Aptitude is about solving problems quickly and accurately. Practice regularly with a timer to improve your speed.
Master basic Vedic Maths tricks for faster calculations.
Strengthen Your Foundation:

Ensure you have a strong understanding of basic mathematical operations like addition, subtraction, multiplication, and division.
Brush up on your fractions, decimals, and percentages.
Use Online Resources and Mock Tests:

Utilize online resources like tutorials, video lectures, and practice questions specific to the UPSC EPFO exam YouTube.
Enroll in mock tests to simulate the exam environment and identify your weak areas. Analyze your performance and revise accordingly.
Previous Years' Papers:

Solve previous years' UPSC EPFO question papers to familiarize yourself with the question format, difficulty level, and recurring themes.
This will help you develop an exam-taking strategy and time management skills.
Focus on Smart Attempts:

Not all questions carry equal marks. Learn to prioritize and attempt questions you're confident about first.
There's usually negative marking, so avoid blind guesswork. Only attempt if you can narrow down the options.
Additional Tips:

Maintain a separate notebook for important formulas and shortcuts for quick reference during revision.
Join online forums or study groups to discuss concepts, share resources, and stay motivated.
Develop a consistent study schedule and dedicate focused time for practicing Quantitative Aptitude.
Remember, consistent practice and a strategic approach are key to success in the UPSC EPFO Quantitative Aptitude section.