Quantitative Aptitude Cheat Sheet

Key Definitions

• Average: Sum of values divided by the number of values. ✅

• Percentage: A fraction expressed as a part of 100. ✅

• Ratio: A relationship between two numbers indicating how many times the first number contains the second. ✅

• Profit/Loss: Difference between cost price and selling price. ✅

Important Concepts

Number Systems

• Natural Numbers: Positive integers starting from 1. ✅

• Whole Numbers: Natural numbers including 0. ✅

• Integers: Whole numbers and their negatives. ✅

Algebra

• Linear Equations: Equations of the first degree. ✅

• Quadratic Equations: Equations of the form ax² + bx + c = 0. ✅

Geometry

• Triangle Properties: Sum of angles = 180°. ✅

• Circle Properties: Circumference = 2πr, Area = πr². ✅

Mensuration

• Area of Rectangle: Length × Breadth. ✅

• Volume of Cube: side³. ✅

Key Formulas

• Average: Average = (Sum of values) / (Number of values) ✅

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

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

• P: Principal, R: Rate, T: Time

• Compound Interest: A = P(1 + r/n)^(nt) ✅

• A: Amount, n: Number of times interest applied per time period

Common Mistakes to Avoid

Common Mistake: Confusing average with median and mode.

Common Mistake: Forgetting to convert percentages to decimals in calculations.

Memory Tricks

Tip: "PEMDAS" — Parentheses, Exponents, Multiplication, Division, Addition, Subtraction (Order of Operations)

Key Diagrams

Triangle:
    /\
   /  \
  /____\

Circle:
   -----
 /       \
|         |
 \_______/

Rectangle:
  __________
 |          |
 |          |
 |__________|