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
- 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 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.

