Short Trick to find LCM of 2 numbers when HCF is given

Duration: 6 min

This video lesson is available to enrolled students.

Return to /learn/ISRO/general-aptitude-reasoning/hcf-lcm/finding-lcm/asset-short-trick-to-find-lcm-of-2-numbers-when-hcf-is-given after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. About Course: About the Course
  2. General Aptitude & Reasoning: Number System, Percentage, Ratio and Proportion (Ratios), Average, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Speed Time and Distance, Mixture and Alligation, Data Interpretation, Algebra, Probability, Permutation and Combination, Venn Diagram, HCF LCM, Divisibility Rules, Age Problems, Pipe and Cistern, Partnership, Linear Algebra, Sequence and Series (Series), Statistics, Powers and Exponents (Surds and Indices), Arithmetic, Mensuration and Geometry, Calculus, Trigonometry, Vectors, Speed Mathematics and Basic Mathematics, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Analogy, Series (Number and Letter Series) (Numerical Relations and Reasoning), Puzzle Solving (Puzzles), Syllogisms, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Calendar, Seating Arrangements, Coding Decoding, Blood Relations, Directions (Direction Test), Clock, Analytical Reasoning (Counting Figures Reasoning), Ranking, Order and Sequence, Logical Sequence Of Words, Inequality, Data Sufficiency, Cubes & Dices
  3. Computer Networks & Cybersecurity: 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, Hardware Basics, Network Security
  4. Programming, Data Structures & Algorithms: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, OOPS with C++, Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
  5. AI, Machine Learning, Big Data & Cloud: Emerging Tech Trends, Artificial Intelligence, Big Data Systems, Approaches to AI, Search Algorithms, Knowledge Representation, Cloud Computing
  6. Digital Logic & Computer Organization: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Register Transfer and Microoperations, Control Unit Design, Programming the Basic Computer
  7. TOC & Compiler: 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, Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization, Run Time Environment
  8. Discrete Mathematics: Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic
  9. Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Unix OS, Linux OS, Distributed Systems
  10. Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management, Object Oriented Technology, HTML Basics, JavaScript-Basics, Java, XML
  11. 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, Database Recovery, Data Warehousing & Mining, Enhanced Data Models, NoSQL
  12. Other Recurring CS Topics: Basics of Computer Graphics, 2-D Geometrical Transforms and Viewing, Multimedia
  13. Live Classes: ISRO Live classes
  14. Full Mock Test:
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 lesson on finding the Least Common Multiple (LCM) of two numbers when their Highest Common Factor (HCF) is known. The video begins with an introduction to the topic, followed by a detailed explanation of the fundamental relationship between the product of two numbers, their HCF, and their LCM. This key formula, 'Product of numbers = HCF * LCM', is highlighted as an 'Important Result'. The instructor demonstrates this formula with a worked example using the numbers 12 and 20, showing how to calculate the HCF and then use the formula to find the LCM. The core of the video is a practical application of this formula to solve a specific problem: 'If HCF of 189 and 297 is 27, find their LCM.' The instructor walks through the calculation step-by-step, multiplying the two numbers (189 x 297) and dividing the result by the HCF (27) to arrive at the final answer of 2079. The video concludes with a summary of the method 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, data-stream background. It then transitions to a lecture screen with a cartoon teacher and a live video feed of the instructor, Yash Jain. The screen shows the topic 'HCF' and 'LCM' with examples of their calculation methods. The instructor introduces the concept of finding the LCM when the HCF is known, setting up the problem: 'If HCF of 189 and 297 is 27, find their LCM.' The on-screen text clearly states the question and the given HCF value.

  2. 2:00 – 5:00 02:00-05:00

    The instructor explains the core formula for solving the problem. He writes on the screen: 'Product of numbers = HCF * LCM'. He then demonstrates this with an example using the numbers 12 and 20, calculating their HCF as 4 and their LCM as 60, and verifying the formula: 12 x 20 = 4 x 60. After establishing this method, he returns to the original problem. He writes the equation: LCM x HCF = 189 x 297. He substitutes the known HCF value of 27, resulting in LCM x 27 = 189 x 297. He then performs the division: LCM = (189 x 297) / 27, which simplifies to LCM = 7 x 297, and finally calculates the result as 2079.

  3. 5:00 – 6:00 05:00-06:00

    The video concludes with a summary of the 'Important Result' formula: 'Product of numbers = HCF * LCM'. The instructor reiterates that this formula is the key to solving such problems efficiently. The final frame is a black screen with an orange and white 'THANKS FOR WATCHING' message, signaling the end of the lesson.

The video presents a clear, step-by-step tutorial on a specific mathematical problem. It effectively uses a combination of visual aids, including on-screen text and handwritten equations, to teach the relationship between HCF and LCM. The instructor first establishes the fundamental formula as a key concept, then applies it to a concrete example to build understanding, and finally uses this knowledge to solve the initial problem. The progression from theory to application provides a solid learning framework for students to solve similar problems.

Loading lesson…