Master the Math.
Secure Your 25 Questions.
Aptitude constitutes 12.5% of the total questions in TNPSC Group 4 and Group 2 exams. Solve faster and smarter with formula sheets, dynamic interactive calculators, and practice questions.
Essential Exam Formulas
Quick-reference cheat sheets for high-yield TNPSC Aptitude modules.
Simplification & Percentages
BODMAS rules, percentages, decimals, fractions, and ratio conversions.
- BODMAS Order:
Bracket ( ), Of, Division (÷), Multiplication (×), Addition (+), Subtraction (-) - Percentage Increase:
Increase % = (Increase Value / Original Value) × 100 - Salary / Consumption Rule:
If A is R% more than B, then B is [R / (100 + R)] × 100 % less than A
HCF & LCM
Common factors, common multiples, division methods, and relationship properties.
- Fundamental Relation:
HCF(a, b) × LCM(a, b) = a × b - LCM of Fractions:
LCM of Numerators / HCF of Denominators - HCF of Fractions:
HCF of Numerators / LCM of Denominators
Simple & Compound Interest
Annual interest rates, principal, accrued amounts, and compound frequency.
- Simple Interest (SI):
SI = (P × T × R) / 100 - Compound Interest (Amount):
A = P × (1 + R/100)^n - Difference for 2 Years:
CI - SI = P × (R / 100)^2
Time & Work
Individual rates, group coordination, pipes, cisterns, and work efficiency.
- Combined Work Rate:
If A takes X days and B takes Y days, together they take (X × Y) / (X + Y) days - Efficiency Rule:
Work Done = Efficiency × Time Taken - Chain Rule:
(M1 × D1 × H1) / W1 = (M2 × D2 × H2) / W2
Mensuration (Area & Volume)
2D shapes, 3D solids, surface area, volumes, and geometric measurements.
- Circle Area & Circumference:
Area = πr², Circumference = 2πr (π ≈ 22/7 or 3.14) - Sphere Volume & Surface Area:
Volume = (4/3)πr³, Surface Area = 4πr² - Cylinder Volume & Curved SA:
Volume = πr²h, Curved Surface Area = 2πrh
Interactive Step-by-Step Solvers
Practice with your own numbers. Enter values and watch the script compute and lay out the complete working steps.
LCM & HCF Step-by-Step Solver
Enter up to three positive integers to compute their Highest Common Factor and Lowest Common Multiple with steps.
Interest Rates Comparison Tool
Compare Simple Interest and Compound Interest (compounded annually) for your principal, rate, and time.
Interactive Revision Quiz
Test your conceptual understanding and calculation speed. Get instant visual feedback and view explanations.
The ratio of two numbers is 3:4 and their HCF is 4. Find their LCM.
Find the compound interest on ₹10,000 for 2 years at 10% per annum, compounded annually.
A can do a piece of work in 10 days and B can do it in 15 days. In how many days can they finish it working together?
Simplify the expression: 125 × 8 ÷ (25 - 5 × 4) + 12
If A's salary is 25% more than B's salary, then by what percentage is B's salary less than A's salary?