Efficiency & Alterate Days Problem (2)
Duration: 6 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: Ratio and Proportion (Ratios), Divisibility Rules, Mixture and Alligation, Permutation and Combination, Logarithm, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Percentage, Average, Mensuration and Geometry, Age Problems, Arithmetic, Statistics, Probability, Profit and Loss, Simple Interest and Compound Interest, Partnership, Speed Mathematics and Basic Mathematics, Algebra, Powers and Exponents (Surds and Indices), Time and Work, Pipe and Cistern, RSSB Specific Videos - Basic Numeracy
- Paper-1 & 2 | Data Interpretation: Data Interpretation
- Paper-1 & 2 | General Mental Ability: Mental Ability, RSSB Specific Videos - Mental Ability
- Paper-1 & 2 | Logical Reasoning and Analytical Ability: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Syllogisms, Seating Arrangements, Blood Relations, Directions (Direction Test), Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Venn Diagram, Analogy, Ranking, Order and Sequence, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Data Arrangement, Logical Sequence Of Words, Crypt Arithmetic
- Paper-1 & 2 | Decision Making and Problem Solving: Selection Decision Table (Decision Making)
- Paper-1 | General Science: Physics, Biology, Chemistry, RSSB Specific Videos
- Paper-1 | General Awareness: State Wise GK, GK- 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, Artificial Intelligence
- Paper-2 | Data Processing (Ms-Office): MS Office Applications
- 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
- Paper 2 | Pedagogy: Child Development, Theories, Concept of Pedagogy, Inclusive Education, Experiential Pedagogy, Assessment & Evaluation, Psychology, Curriculum Framework & Reforms, National Education Policy (NEP) 2020
- Live Classes: RSSB Live Sessions
- Paper 1 - Full Mock Tests:
- Paper 2 - Full Mock Tests:
- BCI Previous Year Papers:
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
This video is a tutorial on solving a work and time problem involving the earnings of men and boys. The instructor, Yash Jain Sir, presents a question where the earnings of 5 men and 7 boys in 6 days and 2 men and 3 boys in 4 days are given, and the task is to find the time for 7 men and 6 boys to earn Rs. 750. The solution method involves setting up equations for the daily earnings of a man (M) and a boy (B), using the given data to find the individual daily earnings, and then calculating the total time required. The video uses a step-by-step approach, first finding the daily earning of a man and a boy, and then applying these values to the final scenario.
Chapters
0:00 – 2:00 00:00-02:00
The video opens with a title card for a 'TIME & WORK' lesson, followed by a screen showing a multiple-choice question (Q1) about the earnings of men and boys. The instructor, Yash Jain Sir, introduces the problem: 'If 5 men with 7 boys can earn Rs. 127.50 in 6 days and 2 men with 3 boys can earn Rs. 35 in 4 days, then find the time in which 7 men with 6 boys will earn Rs. 750.' The options are (A) 20 days, (B) 25 days, (C) 15 days, (D) 30 days. The instructor begins to solve the problem by setting up the first equation: 5M + 7B = 127.50 in 6 days, which simplifies to 5M + 7B = 21.25 per day.
2:00 – 5:00 02:00-05:00
The instructor continues to solve the problem by setting up the second equation from the given data: 2M + 3B = 35 in 4 days, which simplifies to 2M + 3B = 8.75 per day. He then uses the method of elimination to solve for the individual daily earnings. He multiplies the first equation (5M + 7B = 21.25) by 2 to get 10M + 14B = 42.5, and the second equation (2M + 3B = 8.75) by 5 to get 10M + 15B = 43.75. By subtracting the first new equation from the second, he finds that B = 1.25. Substituting this value back, he finds M = 2.5. The instructor then calculates the daily earning of 7 men and 6 boys as 7(2.5) + 6(1.25) = 17.5 + 7.5 = 25.
5:00 – 6:23 05:00-06:23
With the daily earning of 7 men and 6 boys established as Rs. 25, the instructor calculates the time required to earn Rs. 750. He sets up the equation: 25 * x = 750, where x is the number of days. Solving for x, he finds x = 750 / 25 = 30 days. The final answer is 30 days, which corresponds to option (D). The video concludes with a summary of the steps and a 'THANKS FOR WATCHING' screen.
The video presents a clear, step-by-step solution to a classic work and time problem. It demonstrates the method of setting up a system of linear equations based on given work rates and then solving for the unknown individual rates. The core concept is that the total work (earnings) is the product of the rate (daily earning) and the time. By first determining the individual daily earnings of a man and a boy, the solution can be extended to any combination of workers. The method of elimination is used effectively to solve the system of equations, and the final answer is derived by simple division of the total amount by the combined daily rate.