MathematicsChapter 6: Permutation and Combination
Round Table
5 people: 4! = 24. One person already sitting: then 4!
Learning objectives
- State the rule or meaning of round table in easy words.
- Apply round table in a clear step-by-step solution.
- Check the conditions, working, and final answer for accuracy.
Definition
5 people: 4! = 24. One person already sitting: then 4! leftover, which matches (5-1)!. A head of table named in a wedding question may make it linear again — read carefully.
Where / symbols
- ROUND TABLE
- 5 people: 4! = 24. One person already sitting: then 4! leftover, which matches (5-1)!. A head of table named in a wedding question may make it linear again — read carefully.
- ROUND TABLE
- 5 people: 4!
Overview
Understand the idea, then apply it:
Main Idea
5 people: 4! = 24. One person already sitting: then 4! leftover, which matches (5-1)!. A head of table named in a wedding question may make it linear again — read carefully.
Examples (n-1)! · Not n! · Relative seats matter
Exam Use
Write the rule first: 5 people: 4! Substitute carefully, show one step per line, and check signs, restrictions, units, and the final result.
Examples State the central idea · Use one accurate detail · Check the final response
WHAT — ROUND TABLE
5 people: 4! = 24. One person already sitting: then 4! leftover, which matches (5-1)!. A head of table named in a wedding question may make it linear again — read carefully.
WHY — Why it matters
This rule is a separate learning unit inside circular permutations. It can be defined, applied, and checked in its own FBISE question.
HOW — How to answer
Write the rule first: 5 people: 4! Substitute carefully, show one step per line, and check signs, restrictions, units, and the final result.
How to answer a round table question
- Read the exact command word and identify what the question asks.
- State the matching idea, rule, or meaning before adding detail.
- Use the unit evidence or mathematical working that directly supports the answer.
- Check accuracy, relevance, and answer length before finishing.
In simple words
A line is n!. A plain round table is (n-1)!. Do not mix them.
Key points
- fix one person
- round table: (n-1)!
- necklace often /2
- focused answer
Exam preparation
Exam Focus
Quick revision
Revision Zone
Review the key facts, formulas and checks before you move on.Round Table
Sticky Notes · Quick Revision
Core Idea
- 5 people: 4!
What to Know
- 5 people: 4! = 24. One person already sitting: then 4! leftover, which matches (5-1)!. A head of table named in a wedding question may make it linear again — read carefully.
Example or Evidence
- (n-1)!
- Not n!
- Relative seats matter
How to Answer
- Write the rule first: 5 people: 4! Substitute carefully, show one step per line, and check signs, restrictions, units, and the final result.
Common Error
- A line is n!. A plain round table is (n-1)!. Do not mix them.
FBISE Exam Check
- State the rule, show the working, and check the answer.
60-second revision
- 5 people: 4!
- (n-1)!
- Not n!
- State the rule, show the working, and check the answer.
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