Person joining or leaving in between

Duration: 12 min

This video lesson is available to enrolled students.

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Inside: a video lesson and guided study material.

Module outline

  1. About Course: About the Course
  2. Section A: General Awareness: Polity, Physics, Biology, Chemistry, Static General Knowledge, History, Geography, Indian Economy, GK- Current Affairs, Evolution of Indian Banking (Banking & Financial Awareness), Environment
  3. Section A: General Intelligence & Reasoning ability: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Analytical Reasoning (Counting Figures Reasoning), Blood Relations, Syllogisms, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Seating Arrangements, Directions (Direction Test), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Selection Decision Table (Decision Making), Logical Sequence Of Words, Crypt Arithmetic, Venn Diagram, Data Arrangement, Inequality, Analogy, Ranking, Order and Sequence, TCS NQT Advanced Reasoning Ability
  4. Section A: Arithmetical & Numerical Ability: 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, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Pipe and Cistern, Mensuration and Geometry, Powers and Exponents (Surds and Indices), Algebra, Probability, Mental Ability, Age Problems, Partnership, Statistics, Arithmetic, Speed Mathematics and Basic Mathematics, Miscellaneous
  5. Section A: English Language & Comprehension: Vocabulary, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Tenses, Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Articles, Sentence Construction, Preposition, Direct and Indirect Speech, Sentence Completion (Fill in the blanks), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Modals, Active Passive Voice (Voice), Sentence Correction (Error Correction), Adverb, Conjunction, Cloze Test (Cloze Passage)
  6. Section A: Hindi Language & Comprehension: भाषा, लिपि, ध्वनि, वर्ण, अक्षर, स्वर, व्यंजन, मात्रा और संयुक्ताक्षर, वर्तनी, वर्ण-विन्यास, अनुस्वार, अनुनासिक, चंद्रबिंदु और ‘र’ के रूप, शब्द, पद और शब्द-भेद, संज्ञा और सर्वनाम, विशेषण और क्रिया, 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, मुहावरे और लोकोक्तियाँ, अपठित गद्यांश और अपठित पद्यांश, Multi-Topic Content (Cross-Concept Material), वर्णमाला
  7. Section B: Programming, Data Structures, OOP & Java: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Java, OOPS with C++, Language Design, Intro to Compilers, Visual Basics, Syntax Analysis: Bottom-Up, Object Oriented Technology
  8. Section B: Computer Networks, TCP/IP & Network Security: Introduction to CN, Data Communication, DLL: Flow Control, DLL: Access 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, Network Access Technologies, Network Security, Society, Law & Ethics, Mobile Computing, Net Layer:Routing Protocol, Cyber Safety and Security
  9. Section B: Teaching Methodology: Child Development, Concept of Pedagogy, Theories, Inclusive Education, Experiential Pedagogy, Assessment & Evaluation, Curriculum Framework & Reforms, National Education Policy (NEP) 2020, Psychology, Teaching-Learning Process, Personality Development, Teaching Methods & Strategies, Learning and Motivation, Learners & Learning Process, Factors Affecting Teaching, Methods of Teaching, Nature, Objectives & Characteristics of Teaching, Teaching-Learning Aids & ICT Integration, Classroom Management & Communication, Evaluation, Assessment & Measurement, Curriculum & School Environment, Inclusive Education & Special Needs, Professional Development & Ethics
  10. Section B: Digital Electronics / Boolean Logic: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Analog-Digital Conversion
  11. Section B: Operating Systems & Linux: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, File Management, Disc Scheduling, Unix OS, Linux OS, Distributed Systems, Windows OS
  12. Section B: Data Base Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Algebra, SQL, File Organization & Indexing, Transaction Management, Concurrency Control, Database Security & Authorization, Database Recovery, Data Warehousing & Mining
  13. Section B: Internet & Web Technologies: Website, Browser & Services, Internet Fundamentals, Web Design & Development, Protocols & Services, Web Publishing & Hosting, Server Side & Security, HTML Basics, CSS, Emerging Technologies, JavaScript-Basics, .Net Programming, Electronic Data Interchange and E-Commerce, XML
  14. Section B: Computer Fundamentals, IT Basics & Architecture: Basics of COA, Cache Memory Organization, Input Output Organisation, Register Transfer and Microoperations, Control Unit Design, Programming the Basic Computer, Terms & Abbreviations, MS Office Applications, Instr Formats & Modes, Floating Point Rep, Artificial Intelligence, साइबर सुरक्षा / Cyber Safety and Security, कंप्यूटर सॉफ़्टवेयर / Computer Software, ऑपरेटिंग सिस्टम / Operating System, वर्ड प्रोसेसिंग (MS Word) / Word Processing (MS Word), कंप्यूटर नेटवर्क / Computer Networks
  15. Section B: Python Language: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  16. Section B: Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management, extras, Fundamentals of Systems and Information Systems
  17. Section B: Design & Analysis of Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
  18. Section B: Mathematics: Linear Algebra, Calculus, Trigonometry, Vectors, Set Theory, Functions, Relations, Propositional and Predicate Logic, Research Process Steps, Graph Theory, Number System & Place Value, Factors, Multiples, Divisibility, HCF & LCM, Mensuration — Perimeter, Area, Surface Area, Volume, Data Handling, Graphs & Probability, Coordinates & Graphs, Higher Mathematics — Trigonometry, Quadratics, Polynomials, Progressions, Statistics, Logarithms, समतल क्षेत्रमिति / Plane Mensuration, प्रतिचयन / Sampling
  19. Section B: Computer Graphics, Multimedia & Mobile Computing: Basics of Computer Graphics, 2-D Geometrical Transforms and Viewing, 3-D Object Representation, Geometric Transformations and Viewing, Multimedia
  20. Section B: Emerging Trends: Emerging Tech Trends, Knowledge Representation, Natural Language Processing
  21. DSSSB Previous Year Paper:
  22. Business Studies and Management: Business Communication, Business Organization and Management, Financial Accounting, Business Economics, Management Information System (MIS), Knowledge Management & New Economy
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video is a lecture on solving time and work problems, a common topic in competitive exams. The instructor, Yash Jain Sir, presents a series of four problems, each with a different scenario involving multiple workers. The core concept taught is that the total work done is the sum of the work done by each individual, which is calculated as (Time Worked / Time to Complete Alone). The video demonstrates a systematic approach: first, defining variables for the time each person takes to complete the work alone, then setting up an equation where the sum of the fractions of work completed by each person equals 1 (the whole work). The first problem involves two people working together for a period before one leaves. The second problem features three people with staggered start and end times. The third problem uses the combined work rates of pairs to find an individual's rate. The fourth problem uses the LCM method to simplify calculations. The instructor uses a digital whiteboard to write out the equations and solve them step-by-step, providing a clear, methodical guide for students.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title card featuring the text 'TIME & WORK' and an illustration of a person working at a computer. It then transitions to a lecture slide for Question 1. The problem states that Gangadhar and Shaktimaan can complete a work in 18 and 24 days respectively. They work together for 8 days, after which Gangadhar leaves, and Shaktimaan finishes the remaining work. The question asks for the number of days Shaktimaan took to finish the remaining work. The instructor, Yash Jain Sir, is visible in a small window in the bottom right corner. The slide also shows the answer as '16/3 days' and the source as 'COGNIZANT 2018'. The instructor begins to explain the problem, setting up the scenario and introducing the concept of work rates.

  2. 2:00 – 5:00 02:00-05:00

    The instructor explains the general formula for time and work problems. He writes on the digital board: 'Time Worked by A / A's alone time + Time Worked by B / B's alone time = 1'. He then applies this to the first problem, defining 'A' as Gangadhar (18 days) and 'B' as Shaktimaan (24 days). He writes the equation: '8/18 + x/24 = 1', where 'x' is the number of days Shaktimaan worked alone. He proceeds to solve the equation step-by-step, first simplifying 8/18 to 4/9, then finding a common denominator of 72, and finally solving for 'x' to get 16/3 days. The instructor emphasizes that the sum of the work done by each person must equal the total work, which is 1.

  3. 5:00 – 10:00 05:00-10:00

    The video transitions to Question 2. The problem states that Ajay, Vijay, and Sujoy can complete a work in 10, 12, and 15 days respectively. They all start together, Ajay leaves after 2 days, and Vijay leaves 3 days before the work is completed. The question asks for the total time taken to complete the work. The instructor sets up the equation: '2/10 + (x-3)/12 + x/15 = 1', where 'x' is the total time. He explains that Ajay worked for 2 days, Vijay worked for (x-3) days, and Sujoy worked for the full 'x' days. He then solves the equation by finding a common denominator of 60, simplifying to '12 + 5(x-3) + 4x = 60', and solving for 'x' to get 7 days. The instructor then moves to Question 3, which states that A and B together can do a work in 12 days, and B and C together can do it in 16 days. After A works for 5 days, B for 7 days, and C for 13 days, the work is completed. The question asks for the number of days C alone would take to finish the work. The instructor sets up the equation: '5/12 + 7/16 + 13/x = 1'.

  4. 10:00 – 11:47 10:00-11:47

    The instructor continues solving Question 3. He simplifies the equation '5/12 + 7/16 + 13/x = 1' by finding a common denominator of 48, which gives '20/48 + 21/48 + 13/x = 1'. This simplifies to '41/48 + 13/x = 1'. He then isolates the term with 'x': '13/x = 1 - 41/48 = 7/48'. Solving for 'x' gives 'x = (13 * 48) / 7', which is approximately 88.57, but the instructor notes this is not among the options. He then re-examines the problem and realizes the work done by A and B is not independent. He corrects the approach by using the combined rates: (A+B)'s 5-day work + (B+C)'s 2-day work + C's 11-day work = 1. He writes the equation: '5/12 + 2/16 + 11/x = 1'. He solves this, finding a common denominator of 48, which gives '20/48 + 6/48 + 11/x = 1', or '26/48 + 11/x = 1'. This simplifies to '11/x = 22/48', and solving for 'x' gives 24 days. The video then moves to Question 4, which involves Hari and Giri working together, with Hari leaving after some days and Giri finishing the remaining work in 47 days. The instructor sets up the equation using the LCM method: 'x/70 + (x+47)/60 = 1'. The video ends with a 'THANKS FOR WATCHING' screen.

The video provides a comprehensive tutorial on solving time and work problems by breaking them down into a systematic process. The central theme is the application of the formula: (Time Worked / Time to Complete Alone) = Fraction of Work Done. The instructor demonstrates this principle across four distinct problem types: two individuals working together and one leaving, three individuals with staggered work periods, using combined work rates to find an individual's rate, and using the LCM method for efficient calculation. The progression from simple to more complex problems, coupled with clear, step-by-step algebraic solutions, equips students with a robust methodology for tackling a wide range of time and work questions in competitive exams.

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