Important Practice Questions on AVERAGE SPEED (1)

Duration: 9 min

This video lesson is available to enrolled students.

Return to /learn/UPPSC-COMPUTER-OPERATOR-GRADE-B/reasoning/speed-time-and-distance/average-speed/asset-important-practice-questions-on-average-speed-1 after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. English Comprehension: Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Reading Comprehension, Vocabulary, Idioms and Phrases, Narrative Sequencing, Critical Reasoning
  2. Reasoning and Aptitude: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Analogy, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Logical Sequence Of Words, Seating Arrangements, Puzzle Solving (Puzzles), Syllogisms, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Data Sufficiency, Selection Decision Table (Decision Making), Calendar, Clock, Cubes & Dices, Data Arrangement, Venn Diagram, Analytical Reasoning (Counting Figures Reasoning), Number System, HCF LCM, Percentage, Ratio and Proportion (Ratios), Average, Profit and Loss, Simple Interest and Compound Interest, Speed Time and Distance, Mensuration and Geometry, Arithmetic, Mixture and Alligation, Age Problems, Data Interpretation, 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, Simplification and Approximation, Assembling and Grouping of Shapes, Transformation of Shapes, Three-Dimensional Patterns and Visualization, Cubes and Dice, Algebra, Traverse Surveying, Clocks and Calendars, Order, Ranking and Sequence, Constraint Puzzles, Syllogisms and Venn Diagrams, Ratio and Proportion, Mensuration, Permutations and Combinations, Project Monitoring, Resources and Safety, Profit, Loss and Discount, Sequences and Series, Powers, Surds and Logarithms, Subject-Verb Agreement, Sentence Completion, Geometry, Probability, Trigonometry, Measurement and Quantity Take-Off, Statistics, Data Sufficiency, Blood Relations, Speed, Time and Distance, Time and Work, Data Interpretation, Sequence and Series (Series), Algebra, Permutation and Combination, Combinatorics
  3. General Awareness: Physics, Chemistry, Biology, Geography, History, Polity, Indian Economy
  4. Computer Fundamentals: Basics of COA, Number System, Number Representation, Semiconductor Memories and Programmable Logic, Timing, Hazards and Testing, Processor Organization and Instructions, Number Systems and Codes, Combinational Logic Design, Combinational Logic Circuits, Number Systems and Codes
  5. Operating System: Introduction to OS, Unix OS, Linux OS
  6. C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  7. OOPS with C++ & Java: OOPS with C++, Java
  8. Database Management System: Basics of DBMS, SQL
  9. MS Office: MS Office Applications
  10. Internet & Web Technologies: Website, Browser & Services, Internet Fundamentals, Web Design & Development, Protocols & Services
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video, presented by Yash Jain from Knowledge Gate, is a tutorial on calculating average speed for round trips where the speeds for the outbound and return journeys are different. The video begins with an introduction to the topic, followed by a detailed solution to a problem where a man travels to his office at 65 km/hr and returns at 75 km/hr. The instructor demonstrates the correct formula for average speed, which is the total distance divided by the total time, and shows that for a round trip, this simplifies to 2 * s1 * s2 / (s1 + s2). He then applies this formula to the given speeds, calculating the average speed as 69.6 km/hr. The lesson continues with a second example involving a cyclist traveling from point A to B at 28 km/hr and returning at 26 km/hr, for which he calculates the average speed to be 26.96 km/hr. The video concludes with a thank you message.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title slide featuring a space-themed graphic with the text 'SPEED, TIME & DISTANCE' and the hashtag '#knowledgegate'. This transitions to a presentation slide with the same title, crediting the instructor as 'By Yash Jain'. The instructor, Yash Jain, appears in a small window in the bottom right corner, introducing the topic of average speed for a round trip. He explains that the average speed is not the arithmetic mean of the two speeds but is calculated as the total distance divided by the total time. He states that for a round trip, the average speed can be found using the formula 2 * s1 * s2 / (s1 + s2).

  2. 2:00 – 5:00 02:00-05:00

    The video presents the first problem: 'A man goes to his office from his home at a speed of 65 km/hr and returns at 75 km/hr. Find his average speed.' The instructor draws a diagram showing 'home' and 'office' with speeds of 65 km/hr and 75 km/hr respectively. He then writes the formula for average speed: 2 * s1 * s2 / (s1 + s2). He substitutes the values: 2 * 65 * 75 / (65 + 75). He calculates the numerator as 2 * 65 * 75 = 9750 and the denominator as 65 + 75 = 140. He then performs the division 9750 / 140, which he simplifies to 975 / 14, resulting in 69.6 km/hr. He confirms this is the correct average speed.

  3. 5:00 – 9:25 05:00-09:25

    The video moves to a second example: 'A cyclist goes from point A to B at a speed of 28 km/hr and returns to point A at a speed of 26 km/hr. Find his average speed.' The instructor draws a diagram with points A and B and the respective speeds. He applies the same formula: 2 * s1 * s2 / (s1 + s2). He substitutes the values: 2 * 28 * 26 / (28 + 26). He calculates the numerator as 2 * 28 * 26 = 1456 and the denominator as 28 + 26 = 54. He then performs the division 1456 / 54, which he simplifies to 728 / 27, resulting in 26.96 km/hr. The video concludes with a thank you slide.

The video provides a clear and structured lesson on calculating average speed for a round trip. It emphasizes the correct method, which is to use the harmonic mean formula 2 * s1 * s2 / (s1 + s2), and explicitly warns against the common mistake of using the arithmetic mean. The instructor uses two distinct, real-world examples to demonstrate the application of this formula, ensuring the concept is well-understood. The progression from the general formula to its application in two different scenarios effectively reinforces the learning objective.

Loading lesson…