Another Short Trick to find HCF of Big Numbers

Duration: 5 min

This video lesson is available to enrolled students.

Return to /learn/ZERO-TO-HERO/aptitude/hcf-lcm/basic-concepts-factors-multiples-prime-composite-numbers/asset-another-short-trick-to-find-hcf-of-big-numbers after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Relational Calculus, Transaction Management, Concurrency Control
  2. Discrete Mathematics: Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic
  3. Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  4. Computer Architecture: Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design
  5. Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Virtual Memory, Disc Scheduling, File Management, Memory Management, Threads & Process Creation
  6. Computer Networks: Introduction to CN, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Network Security, Hardware Basics
  7. Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  8. Algorithms: Algorithm Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Time Complexity Analysis
  9. Theory Of Computation: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Complexity Theory
  10. Compiler Design: Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization
  11. C language: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums
  12. Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  13. Emerging Trends & AI: Emerging Tech Trends, Artificial Intelligence
  14. Computer Graphics: Basics of Computer Graphics, 2-D Geometrical Transforms and Viewing
  15. Aptitude: Percentage, Ratio and Proportion (Ratios), Logarithm, HCF LCM, Divisibility Rules, Average, Sequence and Series (Series), Number System, Powers and Exponents (Surds and Indices), Algebra, Permutation and Combination, Probability, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Pipe and Cistern, Speed Time and Distance, Mixture and Alligation, Mensuration and Geometry, Mental Ability, Age Problems, Partnership, Statistics, Data Interpretation, Arithmetic, Speed Mathematics and Basic Mathematics, TCS NQT Advanced Quantitative Ability, Gamified / Game Based Aptitude, Linear Algebra, Trigonometry
  16. Reasoning: Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Syllogisms, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Seating Arrangements, Blood Relations, Directions (Direction Test), Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Selection Decision Table (Decision Making), Logical Sequence Of Words, Crypt Arithmetic, Venn Diagram, Data Arrangement, Inequality, Analogy, Ranking, Order and Sequence, TCS NQT Advanced Reasoning Ability
  17. English (Verbal Ability): Vocabulary, Noun, Pronoun, Adjectives, Preposition, Articles, Direct and Indirect Speech, Tenses, Conjunction, Subject Verb Agreement (Verb Noun Agreement), Modals, Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Verbal Analogy (Word Based Analogy), Sentence Construction, Active Passive Voice (Voice), Determiner, Facts, Inference and Judgements, Adverb, Interjection, Verb, English Writing Ability
  18. Engineering Mathematics: Calculus, Vectors
  19. GATE Live Class Recordings 2026: GATE 2026 Live Class
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video, presented by Yash Jain from Knowledge Gate Eduventures, is a tutorial on finding the Highest Common Factor (HCF), also known as the Greatest Common Divisor (GCD). The video begins with an introduction to the topic, defining HCF and LCM, and then transitions to a practical problem: finding the GCD of three large numbers—1365, 1560, and 1755. The instructor demonstrates the prime factorization method as the primary technique. He systematically breaks down each number into its prime factors, writing the factor trees on the screen. For 1365, he shows the factorization as 3 × 5 × 7 × 13. For 1560, he factors it as 2³ × 3 × 5 × 13. For 1755, he factors it as 3³ × 5 × 13. The video concludes by identifying the common prime factors among all three numbers—3, 5, and 13—and multiplying them to find the GCD, which is 195. The final answer is confirmed as option (b) 195.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title card for 'LCM & HCF' and then transitions to a classroom setting. An animated teacher stands by a green chalkboard that displays the text 'Highest Common Common Factor Factor (HCF)'. The instructor, Yash Jain, is visible in a small window. The video then moves to a new slide titled 'HCF of Big Numbers', which presents a multiple-choice question: 'Find the GCD of 1365, 1560, 1755?' with options (a) 95, (b) 195, (c) 295, (d) None of these. The instructor begins to explain the problem, setting up the context for the lesson.

  2. 2:00 – 5:00 02:00-05:00

    The instructor begins the solution by demonstrating the prime factorization of the first number, 1365. He writes a factor tree, dividing 1365 by 3 to get 455, then 455 by 5 to get 91, and finally 91 by 7 to get 13. He concludes that 1365 = 3 × 5 × 7 × 13. He then proceeds to factor 1560, writing 1560 = 2³ × 3 × 5 × 13. Next, he factors 1755, showing 1755 = 3³ × 5 × 13. After establishing the prime factorization of all three numbers, he identifies the common prime factors: 3, 5, and 13. He multiplies these common factors (3 × 5 × 13) to find the GCD, which is 195. He then circles the correct answer, (b) 195, on the screen.

  3. 5:00 – 5:05 05:00-05:05

    The video concludes with a black screen displaying the text 'THANKS FOR WATCHING' in white and orange letters. This is a standard closing slide for the educational content.

The video provides a clear, step-by-step demonstration of how to find the GCD of three large numbers using prime factorization. It begins by introducing the concept of HCF and then applies it to a specific problem. The core of the lesson is the method of breaking down each number into its prime factors, which is visually represented through factor trees. The key learning point is that the GCD is the product of the common prime factors. The video effectively uses on-screen annotations to guide the viewer through the calculation, making the process easy to follow and understand.

Loading lesson…