SSC CGL and CHSL Mathematics Cheat Sheet

Key Definitions

• Arithmetic Mean: Average of a set of numbers.

• Median: Middle value in a sorted list.

• Mode: Most frequently occurring number in a dataset.

Important Concepts

Number System

• Types: Natural, Whole, Integers, Rational, Irrational.

• LCM & GCD: Least Common Multiple and Greatest Common Divisor.

Algebra

• Quadratic Equation: ax^2 + bx + c = 0

• Roots: x = (-b ± √(b² - 4ac)) / 2a

Geometry

• Properties of triangles, circles, quadrilaterals.

• Pythagorean Theorem: a² + b² = c²

Mensuration

• Area of a rectangle: A = l × b

• Volume of a cylinder: V = πr²h

Key Formulas

• Percentage: Percentage = (Part/Whole) × 100

• Simple Interest: SI = (P × R × T) / 100

• P: Principal, R: Rate, T: Time

• Compound Interest: CI = P(1 + r/n)^(nt) - P

• n: Number of times interest applied per time period

Common Mistakes to Avoid

Common Mistake: Confusing LCM with GCD; remember LCM is the smallest common multiple.

Memory Tricks

Tip: "PEMDAS" — Parentheses, Exponents, Multiplication, Division, Addition, Subtraction (order of operations).

Key Diagrams

Triangle:
    /|
   / |
  /  |
 /___|

Circle:
    .--.
  .'    '.
 /        \
|          |
 \        /
  '.___.'