Short Trick to find HCF of Big Numbers

Duration: 10 min

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Inside: a video lesson and guided study material.

Module outline

  1. Paper 1 | Reasoning Test: 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, Puzzle Solving (Puzzles), Venn Diagram, Analogy, Ranking, Order and Sequence, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Selection Decision Table (Decision Making), Logical Sequence Of Words, Cubes & Dices, Analytical Reasoning (Counting Figures Reasoning), Calendar, Alphabet and Word Tests, Numerical Reasoning, Number System, Averages, Mixtures and Alligation, Percentages, Series Completion, Analogy and Classification, Patterns in Two-Dimensional Figures, Coding and Decoding, Mathematical Operations, Direction Sense, Algebra, Logical Deduction and Induction, Syllogisms and Venn Diagrams, Critical Reasoning, Order, Ranking and Sequence, Reading Comprehension, Profit, Loss and Discount, Constraint Puzzles, Speed, Time and Distance, Traverse Surveying, Ratio and Proportion, Time and Work, Mensuration, Permutations and Combinations, Clocks and Calendars, Data Interpretation, Assembling and Grouping of Shapes, Transformation of Shapes, Three-Dimensional Patterns and Visualization, Cubes and Dice, Vocabulary, Blood Relations, Data Sufficiency
  2. Paper 1 | Numerical Analysis: Number System, HCF LCM, Percentage, Ratio and Proportion (Ratios), Average, Sequence and Series (Series), Powers and Exponents (Surds and Indices), Algebra, Statistics, Data Interpretation, Mental Ability, Arithmetic, Logarithm, Profit and Loss, Simple Interest and Compound Interest, Speed Time and Distance, Mixture and Alligation, Mensuration and Geometry, Permutation and Combination, Probability, Sequences and Series, Powers, Surds and Logarithms, Subject-Verb Agreement, Sentence Completion, Geometry, Sentence Structure and Correction, Data Sufficiency, Trigonometry, Measurement and Quantity Take-Off, Signal Space and Optimum Detection, Probability, Statistics, Algebra, Time and Work, Speed, Time and Distance, Data Interpretation, Graph Theory, Combinatorics
  3. Paper 1 | General Knowledge: State Wise GK, History, Geography, GK- Current Affairs, Static General Knowledge, Polity, Indian Economy
  4. Paper 1 | DBMS: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Transaction Management, Concurrency Control, Relational Calculus, Database Security & Authorization, Database Recovery
  5. Paper 1 | Data Communication & Network: Introduction to CN, Data Communication, 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, Security in Mobile and Wireless Computing, Input Output Organisation, File Management, Hardware Basics, Terms & Abbreviations, Protocols & Services, Network Access Technologies, Cyber Safety and Security, Basics of COA
  6. Paper 2 | System Analysis & Design: Fundamentals of Systems and Information Systems, SDLC and Development Approaches, Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Documentation and Software Requirements Specification (SRS), SDD and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management, Security, Risk Management & Maintenance, extras
  7. Paper 2 | Programming Language (Java): Java Fundamentals, OOPS with Java, Array, String, IO & References, Generic & Collections, Multithreading, Java, Miscellaneous, Control Flow, OOPS with C++, Stack, C Fundamentals, Arrays & Pointers, Object Oriented Technology, Control Flow & Looping, Introduction to Python
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video, presented by Yash Jain from Knowledge Gate Eduventures, provides a comprehensive tutorial on finding the Highest Common Factor (HCF) of large numbers. The video begins with an introduction to the topic, defining HCF and explaining its relationship with LCM. The core of the lesson focuses on a practical method for simplifying the calculation of HCF for large numbers by first dividing all numbers by a common factor, typically 10, to reduce them to smaller, more manageable values. This is demonstrated with the example HCF(750, 6300, 18900), where the numbers are divided by 10 to get 75, 630, and 1890. The video then applies the standard prime factorization method to these reduced numbers, showing the step-by-step process of dividing by common prime factors (2, 3, 5) until the numbers are co-prime. The final HCF of the reduced numbers is calculated as 15. The video concludes by multiplying this result by the initial common factor (10) to obtain the correct HCF of the original large numbers, which is 150. The lesson is reinforced with a second example, HCF(108, 288, 360), which is simplified by dividing by 2 to get 54, 144, and 180, and then further reduced to 27, 72, and 90, and so on, to find the HCF of 36. The video uses a digital whiteboard for all calculations and includes a copyright notice.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title card displaying 'LCM & HCF' against a digital background. It then transitions to a classroom setting with a cartoon teacher and a live instructor, Yash Jain. The topic is introduced as 'Highest Common Common Factor (HCF)'. The instructor explains that the video will cover the HCF of big numbers, setting the stage for the main lesson.

  2. 2:00 – 5:00 02:00-05:00

    The instructor presents the first example: HCF(750, 6300, 18900). He demonstrates the method of simplifying the problem by dividing all three numbers by 10, as they are all divisible by 10. This reduces the problem to finding HCF(75, 630, 1890). He then begins the prime factorization process on the reduced numbers, starting by dividing by 2, 3, and 5, and writing down the resulting quotients.

  3. 5:00 – 10:00 05:00-10:00

    The instructor continues the prime factorization for HCF(75, 630, 1890). He divides the numbers by 3, then by 5, and then by 3 again, showing the step-by-step reduction. The process reveals that the common factors are 3 and 5, and the final co-prime numbers are 1, 1, and 1. He calculates the HCF of the reduced numbers as 3 x 5 = 15. He then multiplies this result by the initial common factor of 10 to get the final answer: 15 x 10 = 150. He confirms this is the correct HCF of the original large numbers.

  4. 10:00 – 10:21 10:00-10:21

    The video presents a second example: HCF(108, 288, 360). The instructor begins by dividing all numbers by 2, resulting in 54, 144, and 180. He continues the process, dividing by 2 again to get 27, 72, and 90. He then divides by 3 to get 9, 24, and 30, and continues to find the HCF of these numbers. The video ends with a 'THANKS FOR WATCHING' screen.

The video provides a clear, step-by-step guide on how to find the HCF of large numbers by first simplifying the problem. The central concept is that if all numbers in a set are divisible by a common factor, the HCF of the original numbers can be found by first dividing all numbers by that common factor, calculating the HCF of the resulting smaller numbers, and then multiplying the result by the initial common factor. This method is demonstrated effectively with two examples, showing the reduction of large numbers to manageable ones through division by common factors (10 and 2), followed by the standard prime factorization technique to find the HCF of the simplified set. The final answer is obtained by reversing the initial simplification step.

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