Short Trick to find (mX + nY) (pX + qY) given x y

Duration: 10 min

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Inside: a video lesson and guided study material.

Module outline

  1. About the Course: About the Course
  2. Section 1 | भाषा (हिंदी) / Language (Hindi): भाषा, लिपि और वर्ण, वर्तनी, वर्ण-विन्यास, अनुस्वार, अनुनासिक, चंद्रबिंदु और ‘र’ के रूप, शब्द, पद और शब्द-भेद, संज्ञा और सर्वनाम, पद-भेद और रूप-विकार, लिंग, वचन, पुरुष और कारक, काल, वाच्य, वाक्य और वाक्य-भेद, संधि, समास, विलोम शब्द, पर्यायवाची शब्द, सामान्य अशुद्धियाँ, अनेक शब्दों के लिए एक शब्द, शब्द-भंडार, अपठित बोध, बहुविषयक सामग्री (विभिन्न अवधारणाओं से संबंधित सामग्री), वर्णमाला
  3. Section 1 | اردو زبان / Language (Urdu) — 22 Questions (Fixed): رسم الخط، حروفِ تہجی اور املا, اسم، ضمیر اور صفت, الفاظ، محاورے اور ضرب الامثال, تفہیمِ عبارت، انشا اور ترجمہ, تفہیم
  4. Section 1 | বাংলা ভাষা / Language (Bengali) — 22 Questions (Fixed): শব্দার্থ, বাগধারা ও ভাষাশুদ্ধি, বাক্য ও বাচ্য, শব্দগঠন ও শব্দভান্ডার, অনুবাদ, বোধপরীক্ষণ ও রচনা
  5. Section 1 | Language (English): Vocabulary, Noun, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Verbs and Tenses, Pronoun, Verb, Adverb, Prepositions and Conjunctions, Parts of Speech, Determiner, Conjunction, Modals, Transformation of Sentences, Direct and Indirect Speech, Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Construction, Sentence Structure and Common Errors, Reading Comprehension, Cloze Test (Cloze Passage), Verbal Analogy (Word Based Analogy), Facts, Inference and Judgements
  6. Section 2 | Primary Maths & Reasoning / प्राथमिक गणित एवं तर्कशक्ति: Ratio and Proportion / अनुपात और समानुपात, Divisibility Rules / विभाज्यता के नियम, Mixture and Alligation / मिश्रण और एलिगेशन, Permutation and Combination / क्रमचय और संचय, Number System / संख्या पद्धति, HCF and LCM / महत्तम समापवर्तक और लघुत्तम समापवर्त्य, Sequences, Series and Combinatorics / अनुक्रम, श्रेणी और संयोजन, Time, Speed and Distance / समय, चाल और दूरी, Series / श्रेणी, Coding-Decoding / कूट लेखन एवं कूट वाचन, Non-Verbal Reasoning / अशाब्दिक तर्क, Percentage / प्रतिशत, Average / औसत, Profit, Loss and Discount / लाभ, हानि और बट्टा, Simple and Compound Interest / साधारण और चक्रवृद्धि ब्याज, Time and Work / समय और कार्य, Solid Mensuration / घन क्षेत्रमिति, Age Problems / आयु संबंधी प्रश्न, Arithmetic / अंकगणित, Simplification, Indices and Surds / सरलीकरण, घातांक और करणी, Algebra / बीजगणित, Probability / प्रायिकता, Trigonometry / त्रिकोणमिति, Syllogisms / न्यायवाक्य, Seating Arrangement and Puzzles / बैठक व्यवस्था एवं पहेलियाँ, Blood Relations / रक्त संबंध, Direction and Distance / दिशा एवं दूरी, Analytical Reasoning (Counting Figures Reasoning) / विश्लेषणात्मक तर्क (आकृति गणना तर्क), Mathematical Operations and Missing Numbers / गणितीय संक्रियाएँ एवं लुप्त संख्या, Calendar and Clock / कैलेंडर एवं घड़ी, Clock / घड़ी, Cubes, Dice and Figure Counting / घन, पासा एवं आकृतियों की गिनती, Venn Diagrams, Syllogism and Inequalities / वेन आरेख, न्याय वाक्य एवं असमानता, Data Arrangement / आँकड़ों की व्यवस्था, Inequality / असमानता, Analogy and Classification / सादृश्यता एवं वर्गीकरण, Order and Ranking / क्रम एवं रैंकिंग, Sets, Relations, Functions and Discrete Mathematics / समुच्चय, संबंध, फलन और विविक्त गणित, Number Systems and Number Theory / संख्या पद्धति और संख्या सिद्धांत, Coordinate Geometry, Vectors and 3D Geometry / निर्देशांक ज्यामिति, सदिश और त्रिविमीय ज्यामिति, Polynomials, Equations and Complex Numbers / बहुपद, समीकरण और सम्मिश्र संख्याएँ
  7. Section 2 | General Awareness (GK + Current Affairs) / सामान्य जागरूकता (GK + समसामयिकी): Polity / राजव्यवस्था, Scientific Achievements and Research / वैज्ञानिक उपलब्धियाँ और अनुसंधान, Biology / जीव विज्ञान, State-Specific General Knowledge / राज्य विशेष सामान्य ज्ञान, Chemistry / रसायन विज्ञान, History / इतिहास, Geography / भूगोल, Indian Economy / भारतीय अर्थव्यवस्था, Environment / पर्यावरण, Current Affairs / समसामयिकी, Static General Knowledge / स्थैतिक सामान्य ज्ञान
  8. Section 3 | Computer System and Org. (CSO): Basics of COA, Floating Point Rep, Cache Memory Organization, Instr Formats & Modes, Programming the Basic Computer, Input Output Organisation, Register Transfer and Microoperations, Control Unit Design
  9. Section 3 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, SQL, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control
  10. Section 3 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Process Synchronization
  11. Section 3 | Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics
  12. Section 3 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Minimum Spanning Trees, Shortest Path Algos
  13. Section 3 | Theory Of Computation & Compiler Design: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization
  14. Section 3 | Emerging Trends (AI, Societal Ethics & MS Office): Computer Fundamentals, Emerging Tech Trends, Society, Law & Ethics, MS Office Applications, Trade, Marketing and Consumer Protection / व्यापार, विपणन एवं उपभोक्ता संरक्षण, Cyber Safety and Security, Computer Software, Operating System, Computer Networks, Word Processing (MS Word), Terms & Abbreviations, Presentation Software (MS PowerPoint), Internet of Things, Cloud Computing
  15. Section 3 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Maintenance and Configuration Management, Software Testing
  16. Section 3 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  17. Section 3 | OOPS, C++, JAVA, HTML: OOPS with C++, Java, HTML Basics, CSS
  18. Section 3 | Java: Java Fundamentals, Array, String, IO & References, OOPS with Java
  19. Section 3 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  20. Section 3 | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  21. Section 3 | Multimedia: Multimedia
  22. BPSC Previous Year Papers:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video, presented by Yash Jain from Knowledge Gate Eduventures, focuses on the mathematical topic of "Ratio & Proportion". The lecture begins by defining a ratio as a comparison of two quantities, visually supported by a slide with colorful dots. The instructor then introduces a general algebraic problem type: given a ratio x:y, find the value of a compound ratio (mx+ny):(px+qy) where m, n, p, and q are constants. He demonstrates this concept with a sample ratio x/y = 5/7. The core of the lecture involves solving specific numerical problems using this general framework. The first problem asks to find 3x+2y : 2x+5y given x:y = 2:3. The instructor meticulously solves this using multiple methods, including direct substitution and assuming a constant of proportionality (k). He then applies the same logic to a second problem involving subtraction: finding 3x-7y : 9x-11y given x:y = 7:9. The video serves as a practical guide for students preparing for exams involving ratio and proportion problems.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video starts with a title slide featuring the text "RATIO & PROPORTION" and a 3D pie chart. The instructor introduces the definition of a ratio as "a comparison of 2 quantities", shown on a slide with colorful dots representing parts and wholes. He then presents a general problem statement on a pink background with space-themed doodles: "Given x : y, find (mx + ny) : (px + qy) where m,n,p,q are constants". To make this concrete, he writes a specific example on the top right: x/y = 5/7. This section sets the theoretical foundation for the algebraic manipulation of ratios that follows. The slide background is pink with space-themed doodles like a rocket and a planet.

  2. 2:00 – 5:00 02:00-05:00

    The instructor transitions to a specific numerical question: "If x : y = 2 : 3, find the value of 3x + 2y : 2x + 5y ?". He begins the solution by writing the ratio as a fraction x/y = 2/3. He then attempts to substitute x = 2y/3 into the target expression (3x+2y)/(2x+5y). He writes out the substitution clearly: 3[2y/3] + 2y in the numerator and 2[2y/3] + 5y in the denominator. He then factors out 'y' from both the numerator and the denominator, showing that y cancels out, leaving a numerical expression. This demonstrates the first method of solving such problems. He also writes the final simplified form on the board.

  3. 5:00 – 10:00 05:00-10:00

    Continuing the solution, the instructor simplifies the expression to (3(2/3) + 2) / (2(2/3) + 5). He calculates the numerator as 2 + 2 = 4 and the denominator as 4/3 + 5 = 19/3. This results in 4 / (19/3), which simplifies to 12/19. He then introduces a second, often faster method: assuming x = 2k and y = 3k. Substituting these into the expression gives (3(2k) + 2(3k)) / (2(2k) + 5(3k)) = (6k + 6k) / (4k + 15k) = 12k / 19k = 12/19. He then moves to a new problem: "If x : y = 7 : 9, find the value of 3x - 7y : 9x - 11y ?". He solves this by substituting x=7 and y=9 directly into the expression, showing the calculation (21-63)/(63-99). He writes the intermediate steps clearly on the screen.

  4. 10:00 – 10:17 10:00-10:17

    The instructor completes the calculation for the second problem. He writes (3(7) - 7(9)) / (9(7) - 11(9)) which equals (21 - 63) / (63 - 99). This simplifies to -42 / -36. He simplifies this fraction to 7/6. The video concludes with a black screen displaying "THANKS FOR WATCHING" in white and orange text, signaling the end of the lecture. The instructor is visible in the bottom right corner throughout the problem-solving sections, providing verbal guidance and ensuring students follow the steps.

The lecture effectively bridges the gap between abstract ratio concepts and practical problem-solving. By starting with a general formula and then applying it to specific numerical examples, the instructor reinforces the method of substitution and simplification. The use of multiple methods (substitution vs. assuming constants) for the same problem highlights the flexibility in solving ratio problems, a key skill for exams. The progression from simple definitions to complex algebraic expressions ensures a comprehensive understanding of the topic. The instructor's clear handwriting and step-by-step approach make the complex algebra accessible to students.

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