All Possible Series that can be formed
Duration: 11 min
This video lesson is available to enrolled students.
Inside: a video lesson and guided study material.
Module outline
- Quantitative Aptitude: Number System, Divisibility Rules, HCF LCM, Arithmetic, Percentage, Ratio and Proportion (Ratios), Average, Powers and Exponents (Surds and Indices), Profit and Loss, Simple Interest and Compound Interest, Mixture and Alligation, Age Problems, Partnership, Algebra, Permutation and Combination, Probability, Logarithm, Mensuration and Geometry, Time and Work, Speed Time and Distance, Data Interpretation, Sequence and Series (Series), Gamified / Game Based Aptitude, Speed Mathematics and Basic Mathematics
- Problem Solving & Reasoning: Coding Decoding, Data Sufficiency, Seating Arrangements, Puzzle Solving (Puzzles), Data Arrangement, Syllogisms, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Inequality, Venn Diagram, Ranking, Order and Sequence, TCS NQT Advanced Reasoning Ability, Crypt Arithmetic, Analytical Reasoning (Counting Figures Reasoning), Series (Number and Letter Series) (Numerical Relations and Reasoning), Logical Sequence Of Words
- Verbal Ability: Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Sentence Completion (Fill in the blanks), Sentence Correction (Error Correction), Subject Verb Agreement (Verb Noun Agreement), Tenses, Articles, Preposition, Modals, Vocabulary
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
This educational video is a comprehensive lecture on number and letter series, a common topic in competitive exams. The instructor, Yash Jain, begins by introducing the topic and its relevance, listing numerous exams such as CAT, XAT, GMAT, and various government and banking exams where these questions appear. The core of the video is a structured analysis of different types of series patterns. A slide titled "All Possible Series" lists nine categories: Difference, Double Difference, Square, Cube, Prime, Multiples, Factors, Series with combinations, and Miscellaneous. The instructor then demonstrates how to solve a specific number series puzzle: 5, 7, 12, 19, 31, 50, ? by analyzing the differences between consecutive terms (2, 5, 7, 12, 19), which form a new series. He identifies this new series as a 'Double Difference' pattern, where the differences themselves follow a rule similar to the original series. By applying this logic, he calculates the next difference (31) and adds it to the last term (50) to find the next number in the series, which is 81. The video uses a digital whiteboard for all explanations and examples, with the instructor's video feed visible in a corner.
Chapters
0:00 – 2:00 00:00-02:00
The video opens with a title card for "NUMBER SERIES & LETTER SERIES" against a green digital matrix background. It then transitions to a presentation slide with the title "NUMBER SERIES - LETTER SERIES". The slide presents a puzzle: "Find the next Number in this series: 5, 7, 12, 19, 31, 50, ?". The instructor, Yash Jain, is visible in a small window at the bottom right, introducing the topic and the problem. The slide also features a list of letters and numbers, and a section titled "Why Study This Topic?" which lists various competitive exams like CAT, XAT, GMAT, and others where this topic is relevant.
2:00 – 5:00 02:00-05:00
The video displays a slide titled "All Possible Series" which lists nine types of series patterns: 1. Difference, 2. Double Difference, 3. Square, 4. Cube, 5. Prime, 6. Multiples, 7. Factors, 8. Series with combinations, and 9. Miscellaneous. The instructor explains that these are the primary patterns to look for when solving series problems. He then begins to analyze the given number series (5, 7, 12, 19, 31, 50, ?) by calculating the first differences between consecutive terms, which are 2, 5, 7, 12, 19. He notes that this new series of differences is similar to the original series, indicating a potential 'Double Difference' pattern.
5:00 – 10:00 05:00-10:00
The instructor continues to analyze the series. He identifies the first differences (2, 5, 7, 12, 19) and then calculates the second differences (3, 2, 5, 7). He observes that the second differences (3, 2, 5, 7) are the same as the first differences of the original series, confirming the 'Double Difference' pattern. He then applies this pattern to find the next term. The last first difference is 19, so the next first difference is 31 (12 + 19). Adding this to the last term of the original series (50) gives the next number: 50 + 31 = 81. He writes the final answer, 81, on the screen.
10:00 – 10:49 10:00-10:49
The video concludes with a black screen displaying the text "THANKS FOR WATCHING" in white and orange. The instructor's video feed is no longer visible. This is the final slide of the presentation, serving as a closing message to the audience.
The video provides a clear, step-by-step methodology for solving number series problems, emphasizing pattern recognition. It begins by establishing the importance of the topic for a wide range of competitive exams. The core of the lesson is the systematic breakdown of series into different types, with a focus on the 'Double Difference' pattern. The instructor uses a specific example to demonstrate the process: by calculating the first differences and then the second differences, he identifies a recursive pattern where the differences themselves follow the same rule as the original series. This methodical approach allows for the logical deduction of the next term, which in this case is 81. The video effectively combines visual aids with verbal explanation to teach a fundamental problem-solving skill.