Effect on Average by Arithmetic Operations

Duration: 6 min

This video lesson is available to enrolled students.

Return to /learn/HEXAWARE-PREPARATION/quantitative-ability/average/effect-on-average-by-arithmetic-operations/asset-effect-on-average-by-arithmetic-operations after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. Quantitative Ability: Speed Mathematics and Basic Mathematics, Percentage, Ratio and Proportion (Ratios), Average, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Pipe and Cistern, Speed Time and Distance, Number System, HCF LCM, Data Interpretation, Age Problems, Mixture and Alligation, Partnership, Algebra, Sequence and Series (Series), Mensuration and Geometry, Arithmetic
  2. Reasoning Ability: Puzzle Solving (Puzzles), Seating Arrangements, Coding Decoding, Blood Relations, Directions (Direction Test), Syllogisms, Data Sufficiency, Ranking, Order and Sequence, Series (Number and Letter Series) (Numerical Relations and Reasoning), Logical Sequence Of Words, Calendar, Clock, Cubes & Dices, Analytical Reasoning (Counting Figures Reasoning), Data Arrangement, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning)
  3. Verbal Ability: Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Vocabulary, Sentence Completion (Fill in the blanks), Active Passive Voice (Voice), Direct and Indirect Speech, Subject Verb Agreement (Verb Noun Agreement), Tenses, Preposition, Articles, Sentence Correction (Error Correction)
  4. Programming Basics (MCQs + Interview): C Programming by Yash Sir, Programming in C++, Java, Python for Placements by Yash Sir
  5. OOPs (MCQs + Interview): Object Oriented Programming (OOPS)
  6. DBMS (MCQs + Interview): Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Transaction Management, Decomposition Properties & 4NF, Concurrency Control, Database Recovery, File Organization & Indexing, Relational Algebra, Database Security & Authorization
  7. SQL (MCQs + Interview): SQL
  8. Operating Systems (MCQs + Interview): Introduction to OS, Process Management, CPU Scheduling, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Process Synchronization, Disc Scheduling, File Management, Security
  9. Computer Networks (MCQs + Interview): Introduction to CN, Data Communication, 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, Network Security, Mobile Technology, Cloud Computing and IoT, Cyber and Info Security
  10. Coding: Coding Questions by Yash Sir
  11. HR Interview: MR & HR Interview Preparation
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.

Loading lesson…