Divisibility Rules of 14 and 15

Duration: 5 min

This video lesson is available to enrolled students.

Inside: a video lesson and guided study material.

Module outline

Numerical Ability & Problem Solving: Speed Mathematics and Basic Mathematics, Arithmetic, Number System, HCF LCM, Divisibility Rules, Percentage, Ratio and Proportion (Ratios), Average, Profit and Loss, Simple Interest and Compound Interest, Mixture and Alligation, Time and Work, Pipe and Cistern, Speed Time and Distance, Age Problems, Partnership, Data Interpretation, Mental Ability, Sequence and Series (Series), Powers and Exponents (Surds and Indices), Algebra, Statistics, Logarithm, 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, Combinatorics
Logical Reasoning: 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, Directions (Direction Test), Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Logical Sequence Of Words, Venn Diagram, Data Arrangement, Inequality, Analogy, Ranking, Order and Sequence, Selection Decision Table (Decision Making), 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, Logical Deduction and Induction, Syllogisms and Venn Diagrams, Critical Reasoning, Order, Ranking and Sequence, Reading Comprehension, Profit, Loss and Discount, Constraint Puzzles, Traverse Surveying, Ratio and Proportion, Mensuration, Permutations and Combinations, Clocks and Calendars, Assembling and Grouping of Shapes, Transformation of Shapes, Three-Dimensional Patterns and Visualization, Cubes and Dice, Vocabulary, Blood Relations
General Knowledge & Current Affairs (India + Rajasthan): History, Geography, Polity, Indian Economy, Static General Knowledge, State Wise GK, GK- Current Affairs, Environment, Physics
Computer Fundamentals & Operating Systems: Basics of COA, Floating Point Rep, Digital Systems & Boolean Basics, Number Representation, Number System, Introduction to OS, File Management, Windows OS, Unix OS, Linux OS, Register Transfer and Microoperations, Virtual Memory
Computer Networks: Introduction to CN, Data Communication, DLL: Error Control, DLL: Access Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Application Layer, Hardware Basics, Network Security
Cyber Security: Cyber Threats and Malware Attacks, Role of Internet and Web Services, Security in Mobile and Wireless Computing, Electronic Data Interchange and E-Commerce, Physical Security and Cryptography Basics, Intrusion Detection Systems (IDS), Cyber Safety and Security, Ethical Hacking
Programming (C & OOP): C Fundamentals, Control Flow, Arrays & Pointers, Functions, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, OOPS with C++, Operators & Expressions, Sorting Algorithms, Java Fundamentals, Java
MS Office & Data Processing: MS Office Applications, Basics of DBMS
Internet & Web Technology: Society, Law & Ethics, Terms & Abbreviations, Keyboard Shortcuts, Emerging Tech Trends, Artificial Intelligence, Emerging Technologies, Internet Fundamentals, Website, Browser & Services, Web Design & Development, Protocols & Services, Web Publishing & Hosting, Server Side & Security

AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video provides a structured lesson on divisibility rules for the numbers 14 and 15. The presentation begins with a colorful, hand-drawn diagram illustrating various divisibility rules, setting a visual context for the topic. The main content is delivered through a series of digital slides. The first slide explains the divisibility rule for 14, stating that a number is divisible by 14 if it is divisible by both 2 and 7. The instructor demonstrates this by checking if 224 is divisible by 2 and 7, using the standard divisibility tests for each. A second, more complex rule for 14 is then introduced: a number is divisible by 14 if the sum of its last two digits and twice the rest of the number is divisible by 14. This is demonstrated with the examples 364 and 1764. The video then transitions to the divisibility rule for 15, which states that a number is divisible by 15 if it is divisible by both 3 and 5. The instructor uses the number 390 as an example, showing that it is divisible by 5 (ends in 0) and by 3 (sum of digits is 12, which is divisible by 3). The video concludes with a 'Thanks for Watching' screen.

Chapters

0:00 – 2:00 00:00-02:00
The video opens with a title card displaying 'DIVISIBILITY RULES' over a background of scattered numbers. This transitions to a colorful, hand-drawn circular diagram titled 'DIVISIBILITY RULES' that visually organizes various divisibility rules for numbers 2 through 10. The instructor, Yash Jain Sir, appears in a small window in the bottom right corner. The first slide of the presentation is shown, titled 'Divisibility Rule of 14'. The on-screen text states that a number is divisible by 14 if it is divisible by 2 and by 7. An example, 224, is provided. The instructor begins to explain the rule, writing '14 = 2 x 7' on the screen to show the factorization.
2:00 – 5:00 02:00-05:00
The instructor continues to explain the divisibility rule for 14. He demonstrates that 224 is divisible by 2 because it is an even number, and he shows the division 224 ÷ 2 = 112. He then checks if 224 is divisible by 7 by performing the division 224 ÷ 7, which results in 32. Since 224 is divisible by both 2 and 7, it is divisible by 14. The instructor then introduces a second rule for 14: 'Add the last two digits to twice the rest. The result must be divisible by 14.' He demonstrates this with the example 364: 3 (the rest) multiplied by 2 is 6, and adding the last two digits (64) gives 70. Since 70 is divisible by 14, 364 is divisible by 14. He repeats this with 1764: 17 (the rest) times 2 is 34, plus 64 gives 98, which is divisible by 14.
5:00 – 5:25 05:00-05:25
The video transitions to a new slide titled 'Divisibility Rule of 15'. The on-screen text states that a number is divisible by 15 if it is divisible by 3 and by 5. An example, 390, is given. The instructor explains that 390 is divisible by 5 because it ends in 0. He then checks for divisibility by 3 by summing the digits: 3 + 9 + 0 = 12, and since 12 is divisible by 3, 390 is divisible by 3. Therefore, 390 is divisible by 15. The video concludes with a 'THANKS FOR WATCHING' screen.

The video presents a clear, step-by-step lesson on divisibility rules, using a combination of visual aids and direct instruction. It begins with a general overview of divisibility rules, then focuses on two specific composite numbers, 14 and 15. For each number, the instructor first explains the rule based on its prime factors (e.g., 14 = 2 x 7), providing a foundational understanding. He then introduces a more advanced, direct rule for 14, demonstrating its application with multiple examples. The lesson is structured logically, moving from simpler concepts to more complex ones, and uses clear, worked examples to reinforce the learning. The consistent use of on-screen text and handwritten calculations ensures that the key information is easily accessible to the viewer.