Square Counting Tricks
Duration: 25 min
This video lesson is available to enrolled students.
Inside: a video lesson and guided study material.
Module outline
- About the Course: About the Course
- Section 1 | Language (Hindi): भाषा, लिपि, ध्वनि, वर्ण, अक्षर, स्वर, व्यंजन, मात्रा और संयुक्ताक्षर, वर्तनी, वर्ण-विन्यास, अनुस्वार, अनुनासिक, चंद्रबिंदु और ‘र’ के रूप, शब्द, पद और शब्द-भेद, संज्ञा और सर्वनाम, विशेषण और क्रिया, लिंग, वचन, पुरुष और कारक, काल, वाच्य, वाक्य और वाक्य-भेद, संधि, समास, विलोम शब्द, पर्यायवाची शब्द, सामान्य अशुद्धियाँ, अनेक शब्दों के लिए एक शब्द, मुहावरे और लोकोक्तियाँ, अपठित गद्यांश और अपठित पद्यांश, Multi-Topic Content (Cross-Concept Material), वर्णमाला
- Section 1 | Language (उर्दू भाषा — 22 प्रश्न (निश्चित)): Spelling & Diacritics, Grammar (اسم, فعل, صفت, ضمیر), Vocabulary, Idioms & Proverbs, Comprehension
- Section 1 | Language (বাংলা / बांग्ला भाषा — 22 प्रश्न (निश्चित)): Bangla Script and Sounds, Bangla Grammar and Usage, Bangla Word Formation and Vocabulary, Reading and Text Interpretation
- Section 1 | Language (English): Vocabulary, Noun, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Tenses, Pronoun, Verb, Adverb, Preposition, Articles, Determiner, Conjunction, Modals, Active Passive Voice (Voice), Direct and Indirect Speech, Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Construction, Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Verbal Analogy (Word Based Analogy), Facts, Inference and Judgements
- Section 2 | Primary Maths & Reasoning: Ratio and Proportion (Ratios), Divisibility Rules, Mixture and Alligation, Permutation and Combination, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Percentage, Average, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Mensuration and Geometry, Age Problems, Arithmetic, Powers and Exponents (Surds and Indices), Algebra, Probability, Trigonometry, Syllogisms, Seating Arrangements, Blood Relations, Directions (Direction Test), Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Venn Diagram, Data Arrangement, Inequality, Analogy, Ranking, Order and Sequence
- Section 2 | General Awareness (GK + Current Affairs): Polity, Physics, Biology, State Wise GK, Chemistry, History, Geography, Indian Economy, Environment, GK- Current Affairs, Static General Knowledge
- Section 3 | Computer System and Org. (CSO): Basics of COA, Floating Point Rep, Cache Memory Organization, Instr Formats & Modes, Programming the Basic Computer, Input Output Organisation, Register Transfer and Microoperations, Control Unit Design
- Section 3 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, SQL, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control
- Section 3 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Process Synchronization
- Section 3 | Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics
- Section 3 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Minimum Spanning Trees, Shortest Path Algos
- Section 3 | Theory Of Computation & Compiler Design: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization
- Section 3 | Emerging Trends (AI, Societal Ethics & MS Office): Artificial Intelligence, Emerging Tech Trends, Society, Law & Ethics, MS Office Applications
- Section 3 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Maintenance and Configuration Management, Software Testing
- Section 3 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
- Section 3 | OOPS, C++, JAVA, HTML: OOPS with C++, Java, HTML Basics, CSS
- Section 3 | Java: Java Fundamentals, Array, String, IO & References
- Section 3 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
- Section 3 | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
- Section 3 | Multimedia: Multimedia
- BPSC Previous Year Papers:
- BPSC Full Mock Tests:
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
This video is a comprehensive tutorial on counting squares in a grid, presented as a lecture. The instructor begins by introducing the topic with a title slide and then demonstrates a method for counting squares in a 4x4 grid by systematically summing the squares of different sizes: 4x4, 3x3, 2x2, and 1x1. He explains that the total number of squares is the sum of the squares of the first n natural numbers, where n is the number of rows or columns. The formula 1² + 2² + 3² + ... + n² = n(n+1)(2n+1)/6 is derived and applied to a 4x4 grid, yielding a total of 30 squares. The lecture then transitions to a more complex problem involving a 50x50 grid, where the same formula is used to calculate the total number of squares. The instructor also demonstrates a different type of grid, a 4x4 grid with overlapping squares, and applies the same counting method. The video concludes with a final summary of the key concepts and a 'Thanks for Watching' screen.
Chapters
0:00 – 2:00 00:00-02:00
The video opens with a title slide that reads "SQUARE COUNTING TRICKS". The instructor, a man in a grey polo shirt, stands in front of a whiteboard and begins his lecture. He introduces the topic of counting squares in a grid, explaining that the number of squares can be found by summing the squares of the first n natural numbers, where n is the number of rows or columns. He mentions that this is a common question in competitive exams like the CAT and other national qualifier tests.
2:00 – 5:00 02:00-05:00
The instructor draws a 4x4 grid on the whiteboard. He explains the method for counting squares by considering different sizes. He writes the numbers 1, 2, 3, 4 along the top and left side of the grid to represent the row and column indices. He then begins to count the squares of each size: 4x4, 3x3, 2x2, and 1x1. He explains that there is 1 square of size 4x4, 4 squares of size 3x3, 9 squares of size 2x2, and 16 squares of size 1x1. He writes the calculation 1 + 4 + 9 + 16 = 30 on the board.
5:00 – 10:00 05:00-10:00
The instructor explains the formula for the sum of squares of the first n natural numbers: 1² + 2² + 3² + ... + n² = n(n+1)(2n+1)/6. He writes this formula on the whiteboard and explains that it can be used to quickly calculate the total number of squares in an n x n grid. He applies the formula to the 4x4 grid, substituting n=4, and calculates 4(4+1)(2*4+1)/6 = 4*5*9/6 = 30. He then moves on to a more complex problem involving a 50x50 grid, where he applies the same formula to calculate the total number of squares.
10:00 – 15:00 10:00-15:00
The instructor draws a different type of grid on the whiteboard, a 4x4 grid with overlapping squares. He explains that the same method can be used to count the squares in this grid. He counts the squares of each size: 4x4, 3x3, 2x2, and 1x1. He writes the calculation 1 + 4 + 9 + 16 = 30 on the board. He then explains that the total number of squares in a 4x4 grid is 30, regardless of the arrangement of the squares.
15:00 – 20:00 15:00-20:00
The instructor draws a 4x4 grid on the whiteboard and explains that the total number of squares in a 4x4 grid is 30. He then draws a 50x50 grid and applies the formula 1² + 2² + 3² + ... + n² = n(n+1)(2n+1)/6 to calculate the total number of squares. He substitutes n=50 into the formula and calculates 50(50+1)(2*50+1)/6 = 50*51*101/6 = 42925. He explains that the total number of squares in a 50x50 grid is 42925.
20:00 – 25:00 20:00-25:00
The instructor draws a 4x4 grid on the whiteboard and explains that the total number of squares in a 4x4 grid is 30. He then draws a 50x50 grid and applies the formula 1² + 2² + 3² + ... + n² = n(n+1)(2n+1)/6 to calculate the total number of squares. He substitutes n=50 into the formula and calculates 50(50+1)(2*50+1)/6 = 50*51*101/6 = 42925. He explains that the total number of squares in a 50x50 grid is 42925.
25:00 – 25:28 25:00-25:28
The video ends with a 'Thanks for Watching' screen. The screen has a blue background with a network of lines and dots. The text 'THANKS FOR WATCHING' is displayed in white capital letters in the center of the screen.
The video provides a clear and structured lesson on counting squares in a grid. It begins with a simple 4x4 grid, demonstrating the method of counting squares of different sizes and then introduces the mathematical formula for the sum of squares. The instructor then applies this formula to a larger 50x50 grid, showing how the method scales. The video also covers a more complex grid with overlapping squares, reinforcing the concept. The progression from a simple example to a more complex one, and the clear explanation of the formula, make the lesson effective for students preparing for competitive exams.