Part 6 - Important Practice Questions
Duration: 9 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
- General Knowledge: Polity, Physics, Biology, State Wise GK, Chemistry, History, Geography, GK- Current Affairs, Indian Economy, Static General Knowledge, Environment, Evolution of Indian Banking (Banking & Financial Awareness)
- Mental Aptitude and Reasoning: Ratio and Proportion (Ratios), Divisibility Rules, Data Interpretation, Permutation and Combination, Number System, Sequence and Series (Series), Speed Time and Distance, Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Vocabulary, Profit and Loss, Arithmetic, Mental Ability, Percentage, Algebra, Mensuration and Geometry, Age Problems, Clock, Calendar, Verbal Analogy (Word Based Analogy), Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Analogy, Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Selection Decision Table (Decision Making), Cubes & Dices, Blood Relations, Venn Diagram, Logical Sequence Of Words, Inequality, Directions (Direction Test), Data Arrangement, Facts, Inference and Judgements, Syllogisms, Seating Arrangements, Ranking, Order and Sequence
- CS | Computer Fundamentals: Basics of COA, Number System, Number Representation, C Fundamentals, Algorithm Analysis, Input Output Organisation
- CS | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, SQL
- CS | Workplace productivity Tools: MS Office Applications, Keyboard Shortcuts
- CS | Computer Networks: Introduction to CN, Data Communication, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Transport Layer Services, Application Layer, Hardware Basics, Network Security
- CS | The Internet: Website, Browser & Services, Internet Fundamentals, Web Design & Development, Web Publishing & Hosting, Server Side & Security, Emerging Technologies
- CS | Emerging Technologies: Artificial Intelligence, Emerging Tech Trends, Introduction to OS, Windows OS, Linux OS, Unix OS, JavaScript-Basics
- CS | Boolean algebra: Digital Systems & Boolean Basics, Boolean Expression, Boolean Minimization, Logic Gates & Hardware
- CS | Data Structures: Introduction to DS, Array, Stack, Queue
- CS | Cryptography: Society, Law & Ethics, Cyber Threats and Malware Attacks, Role of Internet and Web Services, Security in Mobile and Wireless Computing, Electronic Data Interchange and E-Commerce, Physical Security and Cryptography Basics, Intrusion Detection Systems (IDS), Cyber Safety and Security
- UP Police Previous Year Papers:
- UP Police Full Mock Tests:
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
This video is a tutorial on Data Sufficiency, a common format in competitive exams like the GMAT or GRE. The instructor, Yash Jain Sir, begins by introducing the topic and the importance of practice. The core of the video is a detailed walkthrough of a specific Data Sufficiency problem. The question asks whether 3^x is less than 500, given that x is an integer. Two statements are provided: Statement 1 is the inequality 4^(x-1) < 4^x - 120, and Statement 2 is the equation x^2 = 36. The instructor systematically analyzes each statement. For Statement 1, he simplifies the inequality to 4^x > 160, which leads to x > 3. For Statement 2, he solves for x, finding x = 6 or x = -6. He then evaluates the sufficiency of each statement individually and together, concluding that Statement 1 alone is sufficient to answer the question, while Statement 2 is not. The video uses a digital whiteboard for all calculations and explanations.
Chapters
0:00 – 2:00 00:00-02:00
The video opens with a title card for 'DATA SUFFICIENCY' and a 'Questions' slide emphasizing the importance of practice. The instructor, Yash Jain Sir, introduces the topic. The main problem is presented on a digital whiteboard: 'Que: If x is an integer, is 3^x less than 500?'. Two statements are listed: 'Statement 1: 4^(x-1) < 4^x - 120' and 'Statement 2: x^2 = 36'. The five multiple-choice options for the Data Sufficiency format are displayed below.
2:00 – 5:00 02:00-05:00
The instructor begins analyzing the problem. He first focuses on the main question, writing '3^x < 500' on the board. He then evaluates Statement 1: '4^(x-1) < 4^x - 120'. He simplifies this by subtracting 4^(x-1) from both sides, resulting in '4^x - 4^(x-1) > 120'. He factors out 4^(x-1), leading to '4^(x-1) * (4 - 1) > 120', which simplifies to '4^(x-1) * 3 > 120'. Dividing by 3 gives '4^(x-1) > 40'. He then calculates 4^3 = 64, which is greater than 40, so x-1 > 3, meaning x > 4. He then evaluates Statement 2: 'x^2 = 36', which gives x = 6 or x = -6.
5:00 – 9:26 05:00-09:26
The instructor now evaluates the sufficiency of the statements. For Statement 1, he concludes x > 4. He then checks if this is sufficient for the main question. He calculates 3^4 = 81, 3^5 = 243, and 3^6 = 729. Since 3^6 = 729 is greater than 500, he determines that x must be less than 6. Therefore, x can be 5, 4, 3, etc. For x=5, 3^5=243<500, which is 'Yes'. For x=6, 3^6=729>500, which is 'No'. Since the answer is not unique, he concludes Statement 1 is not sufficient. For Statement 2, x=6 or x=-6. For x=6, 3^6=729>500, so 'No'. For x=-6, 3^(-6) is a fraction less than 1, so 'Yes'. Since the answer is not unique, Statement 2 is not sufficient. He then considers both statements together, but since Statement 1 is not sufficient, the combination cannot be sufficient. He concludes that the answer is (e) Both statements put together are not sufficient.
The video provides a comprehensive, step-by-step analysis of a Data Sufficiency problem. It demonstrates the core methodology: first, understand the question and the information required. Then, evaluate each statement independently to determine if it provides a unique answer. The instructor correctly identifies that Statement 1 leads to a range of values for x (x > 4) that result in both 'Yes' and 'No' answers to the main question, making it insufficient. Similarly, Statement 2 yields two different values for x, leading to different answers, making it insufficient. The video effectively teaches the process of testing sufficiency by finding counterexamples, which is a key skill for this type of question.