Concept of Reminders (Part 4)

Duration: 18 min

This video lesson is available to enrolled students.

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Inside: a video lesson and guided study material.

Module outline

  1. Child Development and Pedagogy: विकास की अवधारणा / Concept of Development, विकास के मनोवैज्ञानिक सिद्धांत / Psychological Theories of Development, व्यक्तिगत भिन्नताएँ, व्यक्तित्व एवं जेंडर / Individual Differences, Personality and Gender, बुद्धि एवं सृजनात्मकता / Intelligence and Creativity, अधिगम एवं इसके सिद्धांत / Learning and Its Theories, बालक कैसे सोचते एवं सीखते हैं / How Children Think and Learn, संवेग, अभिप्रेरणा, मानसिक स्वास्थ्य एवं निर्देशन / Emotion, Motivation, Mental Health and Guidance, समावेशी शिक्षा / Inclusive Education, शिक्षण-अधिगम प्रक्रिया / Teaching-Learning Process, शिक्षण विधियाँ एवं रणनीतियाँ / Teaching Methods and Strategies, आकलन एवं मूल्यांकन / Assessment and Evaluation, पाठ्यचर्या और विद्यालयी गतिविधियाँ / Curriculum and School Activities, पाठ योजना और शिक्षण कौशल / Lesson Planning and Teaching Skills, शिक्षण संसाधन और शैक्षिक प्रौद्योगिकी / Teaching Resources and Educational Technology, कक्षा प्रबंधन और सम्प्रेषण / Classroom Management and Communication, शिक्षक पहचान और व्यावसायिक विकास / Teacher Identity and Professional Development, शैक्षिक विचारक, उद्देश्य एवं राष्ट्रीय नीतियाँ / Educational Thinkers, Aims and National Policies, विद्यालय नेतृत्व और प्रशासन / School Leadership and Administration, जीवन कौशल, मूल्य, शांति एवं पर्यावरण शिक्षा / Life Skills, Values, Peace and Environmental Education, पर्यावरण अध्ययन का शिक्षणशास्त्र / Pedagogy of Environmental Studies, विज्ञान शिक्षण शास्त्र / Science Pedagogy, संविधान, आयोग, अधिनियम एवं योजनाएँ / Constitution, Commissions, Acts and Schemes in Education, कंप्यूटर हार्डवेयर एवं परिधीय उपकरण / Computer Hardware and Peripherals
  2. Language I — Hindi: भाषा, लिपि और वर्ण-विचार, संधि, शब्द-स्रोत और शब्द-रचना, समास, शब्द-भेद: विकारी और अविकारी, लिंग, वचन, कारक, काल और वाच्य, वाक्य-विचार और शुद्ध लेखन, शब्द-भंडार, रस, छंद, अलंकार और शब्द-शक्ति, हिंदी साहित्य, अपठित बोध, हिंदी शिक्षणशास्त्र
  3. Language II — English: Sounds, Spelling and Word Formation, Parts of Speech, Nouns and Pronouns, Articles, Determiners and Adjectives, Verbs and Modals, Tenses and Subject–Verb Agreement, Adverbs, Prepositions and Conjunctions, Sentence Structure, Voice and Narration, Vocabulary, Sentence Correction and Writing Skills, Poetry and English Literature, Reading Comprehension, Pedagogy of English Language
  4. Language II — Urdu: رسم الخط، املا اور تلفظ, ذخیرۂ الفاظ, قواعد, محاورے اور ضرب الامثال, شعر و سخن, اردو ادب کی تاریخ, تفہیمِ عبارت, اردو کی تدریس
  5. Language II — Sanskrit: वर्णविचारः एवं संज्ञाप्रकरणम्, सन्धिप्रकरणम्, शब्दरूपाणि, धातुरूपाणि, कारकाणि एवं विभक्तयः, उपसर्गाः एवं अव्ययानि, प्रत्ययप्रकरणम्, समासप्रकरणम्, वाच्यप्रकरणम्, संख्याज्ञानम्, शब्दज्ञानम् एवं अनुवादः, अपठितावबोधनम्, संस्कृतसाहित्यम् एवं काव्यशास्त्रम्, संस्कृतशिक्षणशास्त्रम्
  6. Mathematics: संख्या पद्धति एवं स्थानीय मान / Number System & Place Value, मूलभूत संक्रियाएँ, सरलीकरण एवं पैटर्न / Basic Operations, Simplification & Patterns, गुणनखंड, विभाज्यता, म.स.प. एवं ल.स.प. / Factors, Divisibility, HCF & LCM, भिन्न एवं दशमलव / Fractions & Decimals, वर्ग, घन, घातांक एवं करणी / Squares, Cubes, Exponents & Surds, मापन: लंबाई, भार, धारिता, समय एवं मुद्रा / Measurement: Length, Mass, Capacity, Time & Money, बीजगणित / Algebra, अनुपात, समानुपात, औसत एवं आयु / Ratio, Proportion, Average & Ages, प्रतिशत, लाभ-हानि एवं ब्याज / Percentage, Profit–Loss & Interest, समय-कार्य एवं चाल-दूरी / Time & Work and Speed–Distance, रेखाएँ, कोण, आकृतियाँ एवं निर्देशांक / Lines, Angles, Shapes & Coordinates, त्रिभुज, चतुर्भुज, वृत्त एवं त्रिकोणमिति / Triangles, Quadrilaterals, Circles & Trigonometry, क्षेत्रमिति: परिमाप, क्षेत्रफल एवं आयतन / Mensuration: Perimeter, Area & Volume, आँकड़ा प्रबंधन, सांख्यिकी एवं प्रायिकता / Data Handling, Statistics & Probability, गणित शिक्षणशास्त्र / Mathematics Pedagogy
  7. Science: प्रौद्योगिकी, मापन एवं गति / Technology, Measurement and Motion, बल, दाब, कार्य एवं ऊर्जा / Force, Pressure, Work and Energy, ऊष्मा एवं ध्वनि / Heat and Sound, प्रकाश / Light, विद्युत एवं चुंबकत्व / Electricity and Magnetism, ब्रह्मांड एवं प्राकृतिक परिघटनाएँ / Universe and Natural Phenomena, पदार्थ एवं उसकी संरचना / Matter and Its Structure, रासायनिक अभिक्रियाएँ, अम्ल, क्षार एवं लवण / Chemical Reactions, Acids, Bases and Salts, धातु, अधातु एवं दैनिक उपयोग की सामग्री / Metals, Non-metals and Materials of Daily Use, सजीव जगत: वर्गीकरण, कोशिका एवं ऊतक / Living World: Classification, Cell and Tissues, पादपों में पोषण, परिवहन एवं जनन / Plants: Nutrition, Transport and Reproduction, मानव शरीर एवं अंग तंत्र / Human Body and Organ Systems, भोजन, पोषण एवं स्वास्थ्य / Food, Nutrition and Health, पर्यावरण एवं पारिस्थितिकी / Environment and Ecology, पर्यावरण, पारिस्थितिकी और वन्यजीव / Environment, Ecology and Wildlife, प्राकृतिक संसाधन, प्रदूषण और जलवायु परिवर्तन / Natural Resources, Pollution and Climate Change
  8. Social Studies/Social Science: प्राचीन भारत का इतिहास / Ancient Indian History, मध्यकालीन भारत का इतिहास / Medieval Indian History, औपनिवेशिक भारत एवं समाज सुधार / Colonial India and Social Reform, भारतीय राष्ट्रीय आंदोलन एवं स्वतंत्र भारत / Indian National Movement and Independent India, विश्व इतिहास एवं अंतरराष्ट्रीय संबंध / World History and International Relations, पृथ्वी, ग्लोब एवं मानचित्र / Earth, Globe and Maps, भौतिक भूगोल / Physical Geography, प्राकृतिक वनस्पति, वन्य जीवन एवं विश्व के प्रदेश / Natural Vegetation, Wildlife and World Regions, भारत का भूगोल / Geography of India, संसाधन एवं विकास / Resources and Development, सामाजिक एवं राजनीतिक जीवन / Social and Political Life, भारतीय संविधान / Indian Constitution, सरकार: केंद्र, राज्य एवं स्थानीय / Government: Union, State and Local, अर्थशास्त्र एवं भारतीय अर्थव्यवस्था / Economics and Indian Economy, सामाजिक विज्ञान शिक्षणशास्त्र / Social Science Pedagogy, पृथ्वी, आकाश और आपदाएँ / Earth, Sky and Disasters, उत्तर प्रदेश सामान्य ज्ञान / Uttar Pradesh GK
  9. अतिरिक्त अभ्यास / Extra Practice (beyond syllabus): भारतीय अर्थव्यवस्था: आँकड़े एवं समसामयिकी / Indian Economy: Data & Current Affairs, भारतीय कला एवं संस्कृति / Indian Art & Culture, विज्ञान एवं प्रौद्योगिकी / Science & Technology, पर्यावरण एवं जलवायु समसामयिकी / Environment & Climate Affairs, रक्षा एवं सुरक्षा / Defence & Security, स्थिर सामान्य ज्ञान / Static General Knowledge, पुरस्कार एवं सम्मान / Awards & Honours, सरकारी योजनाएँ, शासन एवं आधारभूत संरचना / Government Schemes, Governance & Infrastructure, पासा एवं घन / Dice & Cubes
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 comprehensive tutorial on solving remainder problems in number systems, a common topic in competitive exams. The video begins with an introduction to the concept of remainders, using a simple division example (7 ÷ 2 = 3 R1) to establish the foundational idea. The main content consists of two complex problems. The first problem involves the sum of the reciprocals of the first 13 natural numbers, expressed as a fraction x/13!. The instructor demonstrates that to find the remainder when x is divided by 11, one must analyze the numerator of the sum after a common denominator is applied. The key insight is that for any term where the denominator is not divisible by 11, the corresponding numerator term will be divisible by 11, leaving only the term where the denominator is 11 as the only non-zero contributor to the remainder. The second problem asks for the remainder when N = (1! + 2! + 3! + ... + 1000!)^40 is divided by 10. The instructor explains that for n ≥ 5, n! is divisible by 10, so all terms from 5! onwards are 0 modulo 10. This simplifies the sum to (1! + 2! + 3! + 4!)^40 = (1 + 2 + 6 + 24)^40 = 33^40. The final step is to find the remainder of 33^40 when divided by 10, which is equivalent to finding the last digit of 33^40. The video concludes with a summary of the problem-solving techniques, emphasizing the use of modular arithmetic and the simplification of large expressions by identifying terms that become zero under the given modulus.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title card for 'NUMBER SYSTEM' and then transitions to a presentation slide. The slide features the title 'NUMBER SYSTEM' and the tagline 'The mysterious world of numbers...'. The instructor, Yash Jain, is visible in a small window. He introduces the topic of the 'Concept of Remainders' and provides a simple example on the board: '7 ÷ 2 = 3 R1', with an arrow pointing to the '1' and labeling it 'Remainder'. This establishes the basic definition of a remainder as the leftover part of a division.

  2. 2:00 – 5:00 02:00-05:00

    The video presents the first problem: 'The expression sigma(1/n) from n=1 to 13 can also be written as x/13!. What would be the remainder if x is divided by 11?'. The instructor begins to solve this by writing the sum as 1/1 + 1/2 + 1/3 + ... + 1/13. He then multiplies the entire sum by 13! to get x, which results in the expression x = 13!/1 + 13!/2 + 13!/3 + ... + 13!/13. He explains that to find x mod 11, he needs to evaluate each term in the sum modulo 11.

  3. 5:00 – 10:00 05:00-10:00

    The instructor analyzes the terms of the sum x = 13!/1 + 13!/2 + ... + 13!/13 modulo 11. He explains that 13! is divisible by 11, so 13! ≡ 0 (mod 11). For any term where the denominator is not 11, the numerator 13! is divisible by 11, making the entire term 0 modulo 11. The only term that is not divisible by 11 is the one where the denominator is 11, which is 13!/11. He simplifies this term to 13 × 12 × 10 × 9 × 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1 = 13 × 12 × 10!. He then states that the remainder is the value of 13 × 12 × 10! modulo 11, which he will calculate in the next step.

  4. 10:00 – 15:00 10:00-15:00

    The instructor calculates the remainder of 13 × 12 × 10! when divided by 11. He uses the property that (p-1)! ≡ -1 (mod p) for a prime p (Wilson's Theorem). Since 11 is prime, 10! ≡ -1 (mod 11). He then simplifies 13 × 12 modulo 11: 13 ≡ 2 (mod 11) and 12 ≡ 1 (mod 11). Therefore, the expression becomes 2 × 1 × (-1) = -2. Since the remainder must be positive, he adds 11 to get 9. The final answer for the first problem is 9. He then transitions to the second problem.

  5. 15:00 – 18:29 15:00-18:29

    The second problem is introduced: 'What is the remainder when N = (1! + 2! + 3! + ... + 1000!)^40 is divided by 10?'. The instructor explains that for n ≥ 5, n! is divisible by 10 (since it contains both 2 and 5 as factors), so n! ≡ 0 (mod 10). This means all terms from 5! to 1000! are 0 modulo 10. The sum simplifies to (1! + 2! + 3! + 4!)^40 = (1 + 2 + 6 + 24)^40 = 33^40. The problem now is to find 33^40 mod 10, which is the last digit of 33^40. He notes that the last digit of 33 is 3, so he needs to find the last digit of 3^40. He then calculates the pattern of the last digit of powers of 3: 3^1=3, 3^2=9, 3^3=7, 3^4=1, and the cycle repeats every 4. Since 40 is divisible by 4, the last digit is 1. The final answer is 1. The video ends with a 'Thank You for Watching' screen.

The video provides a clear and structured lesson on applying modular arithmetic to solve complex remainder problems. It begins with a fundamental concept and progresses to two distinct, challenging problems. The first problem demonstrates the power of simplification by identifying that only one term in a large sum contributes to the remainder when the modulus is a prime number, leveraging Wilson's Theorem. The second problem illustrates the technique of reducing a sum by recognizing that terms beyond a certain point become zero modulo the divisor. The core teaching method is the step-by-step breakdown of complex expressions into manageable parts, using properties of factorials and modular arithmetic to arrive at the solution. The progression from a simple example to two advanced problems effectively builds the viewer's problem-solving skills for competitive exams.

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