The Railway Recruitment Board (RRB) conducts some of the most competitive exams in India, including the RRB Group D and RRB NTPC (Non-Technical Popular Categories) exams. One of the most scoring sections in both exams is Mathematics, which tests candidates on fundamental quantitative concepts and problem-solving speed.
To help aspirants strengthen their preparation, here’s a complete list of important Maths formulas for RRB Group D and NTPC 2025, covering topics from Arithmetic, Algebra, Geometry, and Mensuration.
Table of Contents
1. Number System Formulas
LCM × HCF = Product of two numbers
Divisibility Rules:
A number divisible by 2 ends with 0, 2, 4, 6, 8.
A number divisible by 3 → sum of digits divisible by 3.
A number divisible by 11 → difference of sum of alternate digits is 0 or multiple of 11.
Sum of n natural numbers = n(n + 1)/2
Sum of squares of n natural numbers = n(n + 1)(2n + 1)/6
2. Ratio & Proportion
Ratio = Quantity 1 / Quantity 2
If a : b = c : d, then a/b = c/d
Direct Proportion: a/b = c/d
Inverse Proportion: a × b = c × d
3. Percentage & Profit-Loss
Percentage = (Value / Total Value) × 100
Profit % = (Profit / Cost Price) × 100
Loss % = (Loss / Cost Price) × 100
Selling Price = Cost Price × (100 ± Profit/Loss %)/100
Discount % = (Discount / Marked Price) × 100
4. Simple & Compound Interest
Simple Interest (SI) = (P × R × T)/100
Compound Interest (CI) = P(1 + R/100)^T – P
Where,
P = Principal, R = Rate of interest, T = Time (years)
5. Time, Speed, and Distance
Speed = Distance / Time
Distance = Speed × Time
Relative Speed:
When moving in same direction → (A – B)
When moving in opposite direction → (A + B)
Average Speed = (2xy) / (x + y)
6. Time & Work
Work = Rate × Time
If A completes work in x days, then A’s 1-day work = 1/x
Combined Work = (x × y)/(x + y)
7. Geometry & Mensuration
Perimeter & Area Formulas:
Rectangle: P = 2(l + b); A = l × b
Square: P = 4a; A = a²
Triangle: A = ½ × b × h
Circle: C = 2πr; A = πr²
Cylinder: Curved Surface Area = 2πrh; Volume = πr²h
Sphere: Surface Area = 4πr²; Volume = (4/3)πr³
8. Algebra & Simplification
(a + b)² = a² + 2ab + b²
(a – b)² = a² – 2ab + b²
(a + b)(a – b) = a² – b²
(a + b + c)² = a² + b² + c² + 2(ab + bc + ca)
Conclusion
Mastering these RRB Group D & NTPC Maths Formulas 2025 can significantly boost your accuracy and speed in the exam. Practice regularly, revise key formulas, and attempt mock tests to strengthen your command over quantitative aptitude.
Stay consistent — success in RRB exams comes from both concept clarity and daily practice.
