Divisibility Rules of 24, 25 and 26
Duration: 10 min
This video lesson is available to enrolled students.
Inside: a video lesson and guided study material.
Module outline
- About the Course: About the Course
- Paper-1 & 2 | Basic Numeracy: अनुपात और समानुपात / Ratio and Proportion, Divisibility Rules, मिश्रण और एलिगेशन / Mixture and Alligation, Permutation and Combination, Logarithm, संख्या पद्धति / Number System, महत्तम समापवर्तक और लघुत्तम समापवर्त्य / HCF and LCM, Sequence and Series (Series), समय, चाल और दूरी / Time, Speed and Distance, प्रतिशत / Percentage, औसत / Average, घन क्षेत्रमिति / Solid Mensuration, Age Problems, Arithmetic, Statistics, Probability, लाभ, हानि और बट्टा / Profit, Loss and Discount, साधारण और चक्रवृद्धि ब्याज / Simple and Compound Interest, Partnership, Speed Mathematics and Basic Mathematics, Algebra, सरलीकरण, घातांक और करणी / Simplification, Indices and Surds, समय और कार्य / Time and Work, Pipe and Cistern, RSSB Specific Videos - Basic Numeracy, समुच्चय, संबंध, फलन और विविक्त गणित / Sets, Relations, Functions and Discrete Mathematics, संख्या पद्धति और संख्या सिद्धांत / Number Systems and Number Theory, निर्देशांक ज्यामिति, सदिश और त्रिविमीय ज्यामिति / Coordinate Geometry, Vectors and 3D Geometry, बहुपद, समीकरण और सम्मिश्र संख्याएँ / Polynomials, Equations and Complex Numbers
- Paper-1 & 2 | Data Interpretation: आँकड़ा निर्वचन / Data Interpretation
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- Paper-1 & 2 | Logical Reasoning and Analytical Ability: श्रेणी / Series, कूट लेखन एवं कूट वाचन / Coding-Decoding, Data Sufficiency, अशाब्दिक तर्क / Non-Verbal Reasoning, Syllogisms, बैठक व्यवस्था एवं पहेलियाँ / Seating Arrangement and Puzzles, रक्त संबंध / Blood Relations, दिशा एवं दूरी / Direction and Distance, Analytical Reasoning (Counting Figures Reasoning), गणितीय संक्रियाएँ एवं लुप्त संख्या / Mathematical Operations and Missing Numbers, कैलेंडर एवं घड़ी / Calendar and Clock, Clock, घन, पासा एवं आकृतियों की गिनती / Cubes, Dice and Figure Counting, वेन आरेख, न्याय वाक्य एवं असमानता / Venn Diagrams, Syllogism and Inequalities, सादृश्यता एवं वर्गीकरण / Analogy and Classification, क्रम एवं रैंकिंग / Order and Ranking, कथन आधारित तार्किक विवेचन / Statement-Based Reasoning, Data Arrangement, वर्णमाला एवं संख्या परीक्षण / Alphabet and Number Test, Crypt Arithmetic
- Paper-1 & 2 | Decision Making and Problem Solving: आँकड़ों की पर्याप्तता एवं निर्णय क्षमता / Data Sufficiency and Decision Making
- Paper-1 | General Science: वैज्ञानिक उपलब्धियाँ और अनुसंधान / Scientific Achievements and Research, Biology, Chemistry, RSSB Specific Videos
- Paper-1 | General Awareness: राज्य विशेष सामान्य ज्ञान / State-Specific General Knowledge, समसामयिकी / Current Affairs
- Paper - 2 | Digital Logic Systems: Digital Systems & Boolean Basics, Logic Gates & Hardware, Combinational Circuit, Sequential Circuits
- Paper-2 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Calculus, Relational Algebra, SQL, NoSQL
- Paper-2 | Data Structures & Algorithms: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Algorithm Analysis, Sorting Algorithms, Intro to Compilers, Hashing
- Paper 2 | Data Communication and Network Security: Introduction to CN, Data Communication, Data Link Layer - Ethernet, DLL: Error Control, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Application Layer, Hardware basics, Network Security, Ethical Hacking
- Paper-2 | Operating Systems: Introduction to OS, Process Management, Memory Management, File Management, Deadlock
- Paper-2 | Computer Organization and Architecture: Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations, Programming the Basic Computer, Number System, Number Representation
- Paper 2 | System Analysis and Design: Fundamentals of Systems and Information Systems, Fundamentals of Software Engineering, SDLC and Development Approaches, Software Documentation and Software Requirements Specification (SRS), SDD and Quality Assurance, Security, Risk Management & Maintenance, Software Testing
- Paper-2 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
- Paper 2 | OOPS , C++ , JAVA: Language Design, OOPS with C++, Java, .Net Programming, Java Fundamentals
- Paper 2 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
- Emerging Trends and AI: Emerging Tech Trends, कंप्यूटर के मूल सिद्धांत / Computer Fundamentals, व्यापार, विपणन एवं उपभोक्ता संरक्षण / Trade, Marketing and Consumer Protection
- Paper-2 | Data Processing (Ms-Office): MS Office Applications, कंप्यूटर सॉफ़्टवेयर / Computer Software, ऑपरेटिंग सिस्टम / Operating System, वर्ड प्रोसेसिंग (MS Word) / Word Processing (MS Word), प्रेज़ेंटेशन (MS PowerPoint) / Presentation Software (MS PowerPoint)
- Paper-2 | Internet and Web Technologies: HTML Basics, CSS, XML, JavaScript-Basics, Internet Fundamentals, Protocols & Services, Web Publishing & Hosting, Server Side & Security, Emerging Technologies, Terms & Abbreviations, Cyber Threats and Malware Attacks, Role of Internet and Web Services, Security in Mobile and Wireless Computing, साइबर सुरक्षा / Cyber Safety and Security, कंप्यूटर नेटवर्क / Computer Networks
- Paper 2 | Pedagogy: वृद्धि और विकास / Growth and Development, विकास के सिद्धांत / Theories of Development, Concept of Pedagogy, समावेशी शिक्षा / Inclusive Education, Experiential Pedagogy, आकलन और मूल्यांकन / Assessment and Evaluation, संज्ञानात्मक प्रक्रियाएँ / Cognitive Processes, समाजीकरण और जेंडर / Socialisation and Gender, National Education Policy (NEP) 2020
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AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
This educational video presents a series of divisibility rules for the numbers 24, 25, and 26, taught by an instructor in a screen-capture format. The lesson begins with the rule for 24, explaining that a number is divisible by 24 if it is divisible by both 3 and 8. The instructor demonstrates this by checking the divisibility of 552, first by summing its digits (5+5+2=12) to confirm divisibility by 3, and then by performing long division by 8. The video then transitions to the rule for 25, which states that a number is divisible by 25 if its last two digits form a number divisible by 25. An example, 134,250, is used to illustrate this, with the last two digits, 50, being divisible by 25. Finally, the video covers the divisibility rule for 26, which has two parts: a number is divisible by 26 if it is divisible by both 2 and 13, or if subtracting 5 times the last digit from 2 times the rest of the number results in a multiple of 26. The instructor demonstrates this with the number 1248, showing that (124 x 2) - (8 x 5) = 208, which is 26 x 8. The video concludes with a 'Thanks for Watching' screen.
Chapters
0:00 – 2:00 00:00-02:00
The video opens with a title slide displaying 'DIVISIBILITY RULES' over a background of scattered numbers. It then transitions to a colorful, hand-drawn diagram titled 'DIVISIBILITY RULES' that illustrates rules for numbers 2 through 10. The main content begins with a slide titled 'Divisibility Rule of 24'. The on-screen text states that a number is divisible by 24 if it is divisible by 3 and by 8. Two examples are given: 552 is divisible by 3 and 8, and 552 is divisible by 3 and 8. The instructor, visible in a small window, begins to explain the rule. The instructor writes '24 = 3 x 8' on the slide to show the factorization.
2:00 – 5:00 02:00-05:00
The instructor demonstrates the divisibility rule for 24 using the number 552. He first checks divisibility by 3 by summing the digits: '5 + 5 + 2 = 12', and since 12 is divisible by 3, the rule is satisfied. He then checks divisibility by 8 using long division, writing '8)552' and performing the calculation: 8 goes into 55 six times (48), subtracting to get 7, bringing down the 2 to make 72, and 8 goes into 72 nine times (72), resulting in a remainder of 0. The instructor confirms that since 552 is divisible by both 3 and 8, it is divisible by 24. He then begins to write the number 552 again to reinforce the example.
5:00 – 9:39 05:00-09:39
The video transitions to the 'Divisibility Rule of 25'. The on-screen text explains that a number is divisible by 25 if the number formed by its last two digits is divisible by 25. An example is given: 134,250, where the last two digits are 50. The instructor writes '50' and circles it, then performs the division 25 into 50, showing it divides evenly. The video then moves to the 'Divisibility Rule of 26'. The first method states a number is divisible by 26 if it is divisible by both 2 and 13. The second method is a more complex rule: subtracting 5 times the last digit from 2 times the rest of the number gives a multiple of 26. An example is provided: 1248. The instructor calculates (124 x 2) - (8 x 5) = 248 - 40 = 208. He then shows that 208 is divisible by 26 (26 x 8 = 208). The video concludes with a 'THANKS FOR WATCHING' screen.
The video provides a clear, step-by-step tutorial on divisibility rules for three composite numbers. It follows a consistent structure: presenting the rule, providing an example, and demonstrating the verification process. The lesson progresses from a rule based on factorization (24) to a rule based on the last two digits (25), and finally to a more complex algebraic rule (26). The use of on-screen writing and a live instructor enhances the learning experience, making the mathematical concepts accessible and easy to follow.