Revision Notes + Formula Sheet
SSC CGL Quantitative Aptitude Quick Revision
🧠Purpose
To help students revise every topic quickly before mock tests or the final exam.
Each topic summary includes core concepts, key formulas, and memory tips.
1. Number System
Key Concepts
- Natural Numbers: 1, 2, 3, …
- Whole Numbers: 0, 1, 2, …
- Integers: …, –2, –1, 0, 1, 2, …
- Prime Numbers: Divisible by 1 & itself only
Formulas & Rules
HCF × LCM = Product of Numbers
2 → last digit even
3 → sum of digits ÷ 3
4 → last two digits ÷ 4
2. Percentage
Core Formulas
% = (Value / Total) × 100
A + B + AB/100
Successive Change Formula
Key Conversions
1/2 = 50%
1/3 = 33â…“%
1/4 = 25%
1/5 = 20%
3. Profit, Loss & Discount
Basic Formulas
Profit = SP – CP
Loss = CP – SP
%Profit = (Profit / CP) × 100
Discount = MP – SP
Advanced Formula
MP = CP × [(100 + Profit%)/(100 - Discount%)]
4. Simple Interest & Compound Interest
Simple Interest
SI = (P × R × T) / 100
Compound Interest
CI = P(1 + R/100)áµ€ - P
Difference (2 years)
P(R/100)²
5. Ratio & Proportion
Basic Concepts
Ratio: a : b = a/b
If a/b = c/d → ad = bc
Compound Ratio: (a:b) × (c:d) = ac:bd
Inverse Ratio: b:a
Application
Used extensively in partnership, mixture, and sharing problems
6. Average
Basic Formula
Average = Sum of quantities / Number of quantities
Advanced Formula
New Avg = Old Avg + (x - Old Avg)/(n + 1)
After adding x to n numbers
7. Time, Speed & Distance
Core Formulas
Speed = Distance / Time
Same direction → (a – b)
Opposite → (a + b)
Conversions
1 km/hr = 5/18 m/s
1 m/s = 18/5 km/hr
8. Time & Work
Basic Concept
Work = Rate × Time
Together Formula
1/T = 1/x + 1/y
If A takes x days, B takes y days
9. Algebra
Key Identities
(a + b)² = a² + b² + 2ab
(a – b)² = a² + b² – 2ab
a³ + b³ = (a+b)(a² – ab + b²)
a³ – b³ = (a–b)(a² + ab + b²)
12. Trigonometry
Basic Identities
sin²θ + cos²θ = 1
tanθ = sinθ / cosθ
cotθ = 1 / tanθ
Key Values
| θ | sin | cos | tan |
|---|---|---|---|
| 0° | 0 | 1 | 0 |
| 30° | 1/2 | √3/2 | 1/√3 |
| 45° | 1/√2 | 1/√2 | 1 |
| 60° | √3/2 | 1/2 | √3 |
| 90° | 1 | 0 | ∞ |
15. Probability & Permutation
Probability
Favorable / Total Outcomes
Permutation
nPr = n! / (n–r)!
Order matters
Combination
nCr = n! / [r!(n–r)!]
Order doesn't matter
🧠Memory Tips
Daily Practice
Smart Revision
Complete SSC CGL Quant Formula Mastery
Regular revision of these formulas will significantly boost your speed and accuracy
"Formulas are the weapons in your SSC CGL arsenal. Master them, and victory is yours."
Master All SSC CGL Formulas!
Join Courage Library for comprehensive formula sheets and revision strategies.
Be a Couragian!