Effect on Average by Arithmetic Operations

Duration: 6 min

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Inside: a video lesson and guided study material.

Module outline

  1. About Course: About the Course
  2. Paper 1 | Quantitative Aptitude: Speed Mathematics and Basic Mathematics, Percentage, Ratio and Proportion (Ratios), Powers and Exponents (Surds and Indices), Logarithm, Sequence and Series (Series), Mensuration and Geometry, Data Interpretation, Average, Arithmetic
  3. Paper 1 | Logical Reasoning: Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Series (Number and Letter Series) (Numerical Relations and Reasoning), Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Analogy, Cubes & Dices, Syllogisms
  4. Paper 1 | English Language: Vocabulary, Noun, Pronoun, Verb, Adjectives, Adverb, Preposition, Conjunction, Interjection, Articles, Tenses, Subject Verb Agreement (Verb Noun Agreement), Modals, Determiner, Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Sentence Construction
  5. Paper 1 | Unit Tests:
  6. Paper 1 | Full-Length Mock Tests:
  7. Paper 2 | Engineering Mathematics: Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic, Linear Algebra, Calculus, Permutation and Combination, Probability, Statistics
  8. Paper 2 | Digital Logic: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  9. Paper 2 | Computer Architecture: Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design
  10. Paper 2 | Programming and Data Structures: 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
  11. Paper 2 | Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos
  12. Paper 2 | Theory Of Computation/Automata Theory: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Complexity Theory
  13. Paper 2 | Compiler Design: Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization, Run Time Environment
  14. Paper 2 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management
  15. Paper 2 | DataBase Management System/DBMS: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery
  16. Paper 2 | Computer Networks: Introduction to CN, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware Basics
  17. Paper 2 | CS/IT Sectional Mock Tests:
  18. Complete Paper Full Mock Test:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This video is a tutorial on solving average-related problems, presented by an instructor named Yash Jain Sir. The lesson begins with a problem (Q1) where the average of a set of numbers is given, and the task is to find the average of a new set of numbers that are each 2 more than the original numbers. The instructor demonstrates that the new average is simply the original average plus 2, which is 36 + 2 = 38. The video then progresses to a second problem (Q2) where the new numbers are each 3 less than the original, leading to a new average of 36 - 3 = 33. A third problem (Q3) shows a new set of numbers that are each 20 less than the original, resulting in an average of 36 - 20 = 16. The fourth problem (Q4) involves numbers that are each 4 times the original, so the new average is 36 * 4 = 144. The final problem (Q5) is a classic age problem: if the current average age of a family is 30, what will the average be after 5 years? The instructor explains that each person's age increases by 5, so the total sum increases by 5 times the number of people, and the new average is 30 + 5 = 35. The video uses a blackboard for calculations and is structured as a series of practice questions to teach a consistent method for solving average problems.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title card displaying the word "AVERAGE" in a futuristic, glowing font against a dark, digital background. It then transitions to a lecture format with a blackboard. The first problem, Q1, is presented: "If the average of 25, 35, 40, 60 is 36. Then what is the average of 27, 22, 37, 42, 62?" The instructor, Yash Jain Sir, begins to solve it by noting that each number in the second set is 2 more than the corresponding number in the first set. He writes the sum of the new numbers as 27 + 22 + 37 + 42 + 62 and calculates the total as 190. Dividing by 5 gives the average of 38, which is the correct answer (b).

  2. 2:00 – 5:00 02:00-05:00

    The video presents a series of four problems. Q2 asks for the average of numbers that are 3 less than the original set (22, 17, 32, 37, 57). The instructor calculates the sum as 165 and divides by 5 to get 33. Q3 presents numbers that are 20 less than the original (5, 4, 7, 8, 12), with a sum of 36 and an average of 7.2. Q4 involves numbers that are 4 times the original (100, 80, 140, 160, 240), with a sum of 720 and an average of 144. The instructor demonstrates that for Q4, the average is 4 times the original average (36 * 4 = 144). The final problem, Q5, is a word problem: "The average age of a family is 30 years. After 5 years, what is the average age of family??" The instructor explains that the total age increases by 5 times the number of family members, so the average increases by 5, resulting in 35 years.

  3. 5:00 – 5:46 05:00-05:46

    The video concludes with a final summary of the problems. The instructor reiterates the method for solving average problems: if all numbers in a set are increased or decreased by a constant value, the average changes by that same value. If all numbers are multiplied by a constant, the average is multiplied by that constant. The final problem on age is solved by adding the time elapsed to the current average. The video ends with a "THANKS FOR WATCHING" screen over a blue, digital background.

The video provides a clear, step-by-step tutorial on solving average problems by leveraging the properties of averages. The core concept demonstrated is that the average of a set of numbers is directly affected by uniform changes to all the numbers in the set. The instructor uses a consistent method: first, identify the relationship between the original and new sets of numbers (e.g., each is 2 more, 3 less, or 4 times the original), and then apply the corresponding change to the given average. This approach is shown to be efficient and reliable for a variety of problem types, including direct calculation, scaling, and real-world applications like age problems. The progression from simple addition/subtraction to multiplication demonstrates a logical expansion of the concept.

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