Syllabus by chapter · অধ্যায়ভিত্তিক সিলেবাস

Arithmetic · 41 questions: Percentage-Based Games-Won Problem, Comparing Compound and Simple Interest to Split an Inheritance, Finding Cost Price from Equal Profit% and Loss%, Simplifying Expressions with Nested Surds, Average of Consecutive Even Numbers, Area of a quadrilateral field via diagonal split
Algebra · 10 questions: Minimum value of a quadratic expression, Deriving x − 1/x from x + 1/x, Rows-and-Columns (Classroom Arrangement) Problem, Bisection Method for x² − 3 = 0, Cost-Quantity Word Problem, Root-Finding Methods and the Bisection Method
Geometry & Mensuration · 24 questions: Broken Pole Problem, Centroid of a triangular plate, Area of a Square Built on a Right Triangle's Side, Longest Side via the Angle-Side Relationship, Magic Triangle Number Arrangement, বৃত্তে অন্তর্লিখিত ত্রিভুজের ক্ষেত্রফল
Number Theory · 5 questions
Probability & Statistics · 8 questions: Sum of Two Dice Probability, Supervised vs Unsupervised Learning; Mean, Median, Mode, Probability of Independent Binary Events, Expected Length of Runs in a Binary Sequence, Min-max normalization of a data set
Mixed Topics · 173 questions: Categorical Syllogism Validity, Distribution of Identical Objects (Stars and Bars), Circular Arrangement Puzzle, Recovering Sets from Union, Intersection, and Difference, Counting Selections with At-Least-One Constraint, The Knights and Knaves Problem

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Start learning: Number System, HCF and LCM · সংখ্যা পদ্ধতি, গসাগু ও লসাগু

Number System, HCF and LCM

Introduction

Almost every competitive exam in Bangladesh — BCS (preliminary and written), Bank recruitment (Bangladesh Bank AD, Combined bank Officer/SO), and IT-officer/computer posts — opens its mathematics section with the Number System and its two most exam-heavy tools: HCF (GCD) and LCM. These topics look elementary, but examiners love them because a single well-chosen question can test factorisation, divisibility, remainders, ratios and even word-problem reasoning at once. If you master this chapter you will comfortably answer 3–6 marks in any typical exam, and you will move faster through later chapters (fractions, ratio, time and work, pipes and cisterns) that silently depend on LCM.

This lesson builds everything from first principles: what a number is, how numbers are classified, the rules that let you test divisibility in seconds, and then a complete, method-by-method treatment of HCF and LCM with the exact shortcuts examiners expect.

Read the whole lesson free with an account · পুরো পাঠ পড়তে বিনামূল্যে সাইন আপ করুন

All 19 lessons · সব পাঠ

Number System, HCF and LCM · সংখ্যা পদ্ধতি, গসাগু ও লসাগু
Fractions, Decimals and Simplification · ভগ্নাংশ, দশমিক ও সরলীকরণ
Percentage · শতকরা
Ratio, Proportion and Partnership · অনুপাত, সমানুপাত ও অংশীদারি
Profit, Loss and Discount · লাভ, ক্ষতি ও বাট্টা
Simple and Compound Interest · সরল ও চক্রবৃদ্ধি সুদ
Average, Age and Mixtures · গড়, বয়স ও মিশ্রণ
Time and Work · সময় ও কাজ
Time, Speed and Distance · সময়, গতি ও দূরত্ব
Algebra: Equations, Indices and Formulas · বীজগণিত: সমীকরণ, সূচক ও সূত্রাবলি
Geometry and Mensuration · জ্যামিতি ও পরিমিতি
Number Series and Mental Ability · সংখ্যা ধারা ও মানসিক দক্ষতা
Probability and Statistics · সম্ভাবনা ও পরিসংখ্যান
Trigonometry and Coordinate Geometry · ত্রিকোণমিতি ও স্থানাঙ্ক জ্যামিতি
Set Theory, Logic and Proofs · সেট তত্ত্ব, যুক্তি ও প্রমাণ
Relations and Functions · রিলেশন ও ফাংশন
Combinatorics and Counting · কম্বিনেটরিক্স ও গণনা
Graph Theory Basics · গ্রাফ থিওরির মূলনীতি
Advanced Counting, Logic and Graph Topics · উন্নত গণনা, যুক্তি ও গ্রাফ বিষয়

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