Short Trick to find HCF by using smallest element

Duration: 10 min

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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 provides a step-by-step tutorial on calculating the Highest Common Factor (HCF) using the 'Least Number' method, which is a variation of the prime factorization technique. The instructor, Yash Jain, begins by introducing the topic and then demonstrates the method with several examples. The first example involves finding the HCF of 6, 12, and 18. The method involves identifying the smallest number among the given numbers (the 'pivot element') and then checking if it divides all other numbers. If it does, it is the HCF. If not, the process is repeated with the next smallest number. The video then applies this method to more complex sets of numbers, such as (8, 16, 20, 28, 44) and (8, 11, 16, 20, 28, 44, 46), consistently demonstrating the process of elimination to find the highest common factor. The video concludes with a final example and a 'Thanks for Watching' screen.

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 lecture slide with a green chalkboard background. The slide is titled '5. HCF using Least Number' and presents the first example: 'HCF (6, 12, 18)'. The instructor, Yash Jain, begins to explain the method, writing the numbers 6, 12, and 18 on the board. He identifies 6 as the smallest number and the 'pivot element' for the method, explaining that the goal is to find the highest common factor by checking divisibility.

  2. 2:00 – 5:00 02:00-05:00

    The instructor continues the first example, demonstrating the 'Least Number' method. He writes '6, 12, 18' and circles the number 6, labeling it the 'pivot element'. He then checks if 6 divides 12 and 18. He writes '6/12 = 2' and '6/18 = 3', indicating that 6 divides both numbers. Since 6 divides all the numbers in the set, he concludes that the HCF is 6, writing 'HCF = 6'. The video then moves to the next example, 'HCF (8, 16, 20, 28, 44)'. He identifies 8 as the pivot element and checks if it divides all other numbers. He writes '8/16 = 2', '8/20 = 2.5', and '8/28 = 3.5', showing that 8 does not divide 20 or 28. He then circles 8 and marks the other numbers with a cross, indicating they are not divisible by 8. He then identifies the next smallest number, 16, as the new pivot element and begins to check its divisibility.

  3. 5:00 – 9:34 05:00-09:34

    The instructor continues with the second example, 'HCF (8, 16, 20, 28, 44)'. He checks if 16 divides 8, 20, 28, and 44, and finds that it does not. He then moves to the next smallest number, 20, and checks its divisibility, finding it fails. He continues this process, checking 28 and 44, all of which fail. He then identifies 4 as a common factor and checks if it divides all numbers, finding that it does. He concludes that the HCF is 4. The video then presents a third example: 'HCF (8, 11, 16, 20, 28, 44, 46)'. He identifies 8 as the pivot element and checks divisibility, finding it fails for 11, 16, 20, 28, 44, and 46. He then checks 11, which fails for 8, 16, 20, 28, 44, and 46. He continues this process, eventually finding that 2 is the only number that divides all the numbers in the set. He concludes that the HCF is 2. The video ends with a 'Thanks for Watching' screen.

The video systematically teaches a specific method for finding the Highest Common Factor (HCF) by using the 'Least Number' approach. The core concept is to start with the smallest number in the set and test if it is a common divisor for all other numbers. If it is, it is the HCF. If not, the process is repeated with the next smallest number until a common divisor is found. This method is demonstrated through three distinct examples, each increasing in complexity, to reinforce the concept. The video effectively uses on-screen writing and clear verbal explanation to guide the viewer through the logical steps of the algorithm, making it a practical tutorial for students learning about HCF.

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