Short Trick to find HCF of Big Numbers

Duration: 10 min

This video lesson is available to enrolled students.

Inside: a video lesson and guided study material.

Module outline

Aptitude: Ratio and Proportion (Ratios), Divisibility Rules, Data Interpretation, Mixture and Alligation, Permutation and Combination, Logarithm, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Percentage, Average, Powers and Exponents (Surds and Indices), Algebra, Probability, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Pipe and Cistern, TCS NQT Advanced Quantitative Ability, Speed Mathematics and Basic Mathematics, Arithmetic, Statistics, Partnership, Age Problems, Mental Ability, Mensuration and Geometry, Linear Algebra, Calculus, Trigonometry, Vectors, Gamified / Game Based Aptitude
Reasoning: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Syllogisms, TCS NQT Advanced Reasoning Ability, Ranking, Order and Sequence, Analogy, Inequality, Data Arrangement, Venn Diagram, Logical Sequence Of Words, Selection Decision Table (Decision Making), Cubes & Dices, Clock, Calendar, Puzzle Solving (Puzzles), Analytical Reasoning (Counting Figures Reasoning), Directions (Direction Test), Blood Relations, Seating Arrangements
Verbal Ability (English): Vocabulary, Noun, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Tenses, Pronoun, Preposition, Articles, Direct and Indirect Speech, Conjunction, 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, Verb
Mega Test:
Grand 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 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

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.
2:00 – 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.
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.
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.