Short Trick to Find Selling Price Quickly

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 the Course: About the Course
  2. Paper-1 & 2 | Basic Numeracy: अनुपात और समानुपात / Ratio and Proportion, Divisibility Rules, मिश्रण और एलिगेशन / Mixture and Alligation, Permutation and Combination, Logarithm, संख्या पद्धति / Number System, महत्तम समापवर्तक और लघुत्तम समापवर्त्य / HCF and LCM, Sequence and Series (Series), समय, चाल और दूरी / Time, Speed and Distance, प्रतिशत / Percentage, औसत / Average, घन क्षेत्रमिति / Solid Mensuration, Age Problems, Arithmetic, Statistics, Probability, लाभ, हानि और बट्टा / Profit, Loss and Discount, साधारण और चक्रवृद्धि ब्याज / Simple and Compound Interest, Partnership, Speed Mathematics and Basic Mathematics, Algebra, सरलीकरण, घातांक और करणी / Simplification, Indices and Surds, समय और कार्य / Time and Work, Pipe and Cistern, RSSB Specific Videos - Basic Numeracy, समुच्चय, संबंध, फलन और विविक्त गणित / Sets, Relations, Functions and Discrete Mathematics, संख्या पद्धति और संख्या सिद्धांत / Number Systems and Number Theory, निर्देशांक ज्यामिति, सदिश और त्रिविमीय ज्यामिति / Coordinate Geometry, Vectors and 3D Geometry, बहुपद, समीकरण और सम्मिश्र संख्याएँ / Polynomials, Equations and Complex Numbers
  3. Paper-1 & 2 | Data Interpretation: आँकड़ा निर्वचन / Data Interpretation
  4. Paper-1 & 2 | General Mental Ability: Mental Ability, RSSB Specific Videos - Mental Ability
  5. Paper-1 & 2 | Logical Reasoning and Analytical Ability: श्रेणी / Series, कूट लेखन एवं कूट वाचन / Coding-Decoding, Data Sufficiency, अशाब्दिक तर्क / Non-Verbal Reasoning, Syllogisms, बैठक व्यवस्था एवं पहेलियाँ / Seating Arrangement and Puzzles, रक्त संबंध / Blood Relations, दिशा एवं दूरी / Direction and Distance, Analytical Reasoning (Counting Figures Reasoning), गणितीय संक्रियाएँ एवं लुप्त संख्या / Mathematical Operations and Missing Numbers, कैलेंडर एवं घड़ी / Calendar and Clock, Clock, घन, पासा एवं आकृतियों की गिनती / Cubes, Dice and Figure Counting, वेन आरेख, न्याय वाक्य एवं असमानता / Venn Diagrams, Syllogism and Inequalities, सादृश्यता एवं वर्गीकरण / Analogy and Classification, क्रम एवं रैंकिंग / Order and Ranking, कथन आधारित तार्किक विवेचन / Statement-Based Reasoning, Data Arrangement, वर्णमाला एवं संख्या परीक्षण / Alphabet and Number Test, Crypt Arithmetic
  6. Paper-1 & 2 | Decision Making and Problem Solving: आँकड़ों की पर्याप्तता एवं निर्णय क्षमता / Data Sufficiency and Decision Making
  7. Paper-1 | General Science: वैज्ञानिक उपलब्धियाँ और अनुसंधान / Scientific Achievements and Research, Biology, Chemistry, RSSB Specific Videos
  8. Paper-1 | General Awareness: राज्य विशेष सामान्य ज्ञान / State-Specific General Knowledge, समसामयिकी / Current Affairs
  9. Paper - 2 | Digital Logic Systems: Digital Systems & Boolean Basics, Logic Gates & Hardware, Combinational Circuit, Sequential Circuits
  10. 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
  11. Paper-2 | Data Structures & Algorithms: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Algorithm Analysis, Sorting Algorithms, Intro to Compilers, Hashing
  12. 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
  13. Paper-2 | Operating Systems: Introduction to OS, Process Management, Memory Management, File Management, Deadlock
  14. 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
  15. 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
  16. Paper-2 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  17. Paper 2 | OOPS , C++ , JAVA: Language Design, OOPS with C++, Java, .Net Programming, Java Fundamentals
  18. 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
  19. Emerging Trends and AI: Emerging Tech Trends, कंप्यूटर के मूल सिद्धांत / Computer Fundamentals, व्यापार, विपणन एवं उपभोक्ता संरक्षण / Trade, Marketing and Consumer Protection
  20. Paper-2 | Data Processing (Ms-Office): MS Office Applications, कंप्यूटर सॉफ़्टवेयर / Computer Software, ऑपरेटिंग सिस्टम / Operating System, वर्ड प्रोसेसिंग (MS Word) / Word Processing (MS Word), प्रेज़ेंटेशन (MS PowerPoint) / Presentation Software (MS PowerPoint)
  21. 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, साइबर सुरक्षा / Cyber Safety and Security, कंप्यूटर नेटवर्क / Computer Networks
  22. Paper 2 | Pedagogy: वृद्धि और विकास / Growth and Development, विकास के सिद्धांत / Theories of Development, Concept of Pedagogy, समावेशी शिक्षा / Inclusive Education, Experiential Pedagogy, आकलन और मूल्यांकन / Assessment and Evaluation, संज्ञानात्मक प्रक्रियाएँ / Cognitive Processes, समाजीकरण और जेंडर / Socialisation and Gender, National Education Policy (NEP) 2020
  23. Live Classes: RSSB Live Sessions
  24. Paper 1 - Full Mock Tests:
  25. Paper 2 - Full Mock Tests:
  26. BCI Previous Year Papers:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video is a tutorial on solving profit and loss problems, presented by a teacher from Knowledge Gate. The video begins with a problem where a person, Jethalal, sells an item for Rs. 720 and incurs a 25% loss, and the task is to find the selling price for a 25% gain. The instructor first uses a 'Trick 1' method, calculating the cost price (CP) as 720 / 0.75 = Rs. 960, and then the new selling price (SP) as 960 * 1.25 = Rs. 1200. He then demonstrates a 'Trick 2' method, which involves setting the CP as 100% and using the ratio of SP to CP to find the new SP. The video then transitions to a second problem: if the cost price of 36 books equals the selling price of 30 books, what is the gain or loss percentage? The instructor solves this using a 'Conventional Method' by assuming a cost price of 'x' per book, leading to a gain of 20%. He then shows a 'Short Trick' method, where the ratio of CP to SP is 30:36, which simplifies to 5:6, directly yielding a 20% gain. The video concludes with a 'Thanks for Watching' screen.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title card for a problem: 'Q1: If Jethalal has to sell an electronic item for Rs. 720, he would lose 25%. In order to gain 25%, he should sell it for ??'. The instructor, Yash Jain, introduces the problem. The screen then transitions to a green chalkboard where the instructor begins to solve the problem using 'Trick 1'. He writes the formula for cost price (CP) as 720 / (1 - 0.25) and the formula for the new selling price (SP) as CP * (1 + 0.25). He also writes the formula for loss (L) as CP - SP and the formula for profit (P) as SP - CP.

  2. 2:00 – 5:00 02:00-05:00

    The instructor continues to solve the first problem on the green chalkboard. He calculates the cost price (CP) as 720 / 0.75, which equals 960. He then calculates the new selling price (SP) for a 25% gain as 960 * 1.25, which equals 1200. He writes the final answer as SP = 1200. The instructor explains that the cost price is 960, and to gain 25%, the selling price should be 1200. He also writes the formula for loss percentage as (Loss / CP) * 100 and the formula for profit percentage as (Profit / CP) * 100.

  3. 5:00 – 10:00 05:00-10:00

    The instructor introduces 'Trick 2' for the first problem. He sets the cost price (CP) as 100%. He then calculates the selling price (SP) for a 25% loss as 75% of CP, which is 720. He uses the ratio 75:100 = 720:CP to find CP, which is 960. He then calculates the new SP for a 25% gain as 125% of CP, which is 1200. He writes the final answer as SP = 1200. The instructor explains that the cost price is 960, and to gain 25%, the selling price should be 1200. He also writes the formula for loss percentage as (Loss / CP) * 100 and the formula for profit percentage as (Profit / CP) * 100.

  4. 10:00 – 12:02 10:00-12:02

    The video transitions to a new problem: 'Q2: The cost price of 36 books is equal to selling price of 30 books. The gain or loss % is __'. The instructor introduces the 'Conventional Method'. He assumes the cost price of one book is 'x'. Therefore, the cost price of 36 books is 36x. The selling price of 30 books is also 36x, so the selling price of one book is 36x/30 = 1.2x. He calculates the profit as SP - CP = 1.2x - x = 0.2x. He then calculates the profit percentage as (0.2x / x) * 100 = 20%. He writes the final answer as 20%. The instructor then introduces the 'Short Trick' method, where the ratio of CP to SP is 30:36, which simplifies to 5:6, directly yielding a 20% gain. The video ends with a 'Thanks for Watching' screen.

The video provides a comprehensive tutorial on solving profit and loss problems using two distinct methods. The first problem demonstrates how to find a new selling price given a loss and a desired gain, using both a direct calculation method and a ratio-based method. The second problem illustrates how to find the gain percentage when the cost price of a certain number of items is equal to the selling price of a different number, using both a conventional algebraic approach and a more efficient 'short trick' based on ratios. The core concept is that profit and loss are calculated based on the cost price, and the key to solving these problems efficiently lies in understanding the relationship between cost price, selling price, and the percentage change.

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