Advanced Analytical Skills β II
Unit 7: Coded Inequalities
Master the art of decoding symbolic inequalities, solving chain comparisons, comparing roots of quadratic equations, and cracking every competitive exam question on this topic.
β±οΈ Time to Complete: 6β8 hours | π 30 MCQs + 8 Short + 3 Long (Bloom's Mapped) | 15 Worked Examples
π― Exams this covers: Bank PO (SBI/IBPS) | SSC CGL | CAT | CLAT | University Aptitude Tests
Opening Hook β When Symbols Replace Logic
π§© The Code That Decides Your Bank Job
It's February 2026. You sit down for your SBI PO Prelims at 10:00 AM in a packed exam centre in Lucknow. 35 reasoning questions. 20 minutes. The clock is ticking. Question 14 appears on screen:
Statements: P Β© Q, Q Β£ R, R @ S
Conclusions: I. P Β© S II. S Β£ P
Your friend panics. You smile. Because you know Β© means >, Β£ means <, @ means =. You decode, chain, and solve in 15 seconds: P > Q < R = S β neither conclusion follows. Answer marked. Next question.
This isn't magic β it's Coded Inequalities. The single most predictable, most scoreable topic in banking exams. 5 questions. Every exam. Guaranteed.
Learning Outcomes β Bloom's Taxonomy Mapped
| Bloom's Level | Learning Outcome |
|---|---|
| π΅ Remember | List the six fundamental inequality symbols (>, <, β₯, β€, =, β ) and recall coded symbol mappings |
| π΅ Understand | Explain how a coded inequality statement translates into a standard mathematical inequality |
| π’ Apply | Decode coded statements and form a single combined chain inequality |
| π’ Analyse | Analyse a given chain to determine which conclusions are definitely true, definitely false, or can't be determined |
| π Evaluate | Evaluate conclusions involving quadratic-root-based inequalities and mixed chains |
| π Create | Create your own coded inequality problem sets and solve advanced multi-statement questions under exam pressure |
Basic Inequalities β The Foundation
Before we decode anything, let's build rock-solid clarity on what inequality symbols actually mean. Every competitive exam question on coded inequalities rests on these six symbols:
π The Six Fundamental Inequality Symbols
| Symbol | Name | Meaning | Example | Read As |
|---|---|---|---|---|
| > | Greater than | Left side is strictly larger than right | 7 > 3 | "7 is greater than 3" |
| < | Less than | Left side is strictly smaller than right | 2 < 9 | "2 is less than 9" |
| β₯ | Greater than or equal to | Left side is larger than or equal to right | 5 β₯ 5 | "5 is at least 5" |
| β€ | Less than or equal to | Left side is smaller than or equal to right | 3 β€ 8 | "3 is at most 8" |
| = | Equal to | Both sides are exactly the same | 4 = 4 | "4 equals 4" |
| β | Not equal to | Both sides are different | 5 β 3 | "5 is not equal to 3" |
Key Properties of Inequalities
1. Transitivity β The Chain Rule
This is the most important property for coded inequalities. If two inequalities share a common element, you can chain them:
This works for >, <, β₯, β€, and = in compatible directions. It does not work when the directions conflict.
2. Reversal Property
Every inequality can be read backwards by flipping the symbol:
3. Combining β₯ and > (Same Direction)
When combining two inequalities going in the same direction, the combined result takes the weaker (broader) symbol:
| Statement 1 | Statement 2 | Combined Result | Rule |
|---|---|---|---|
| A > B | B > C | A > C | Strict + Strict = Strict |
| A β₯ B | B β₯ C | A β₯ C | Non-strict + Non-strict = Non-strict |
| A > B | B β₯ C | A > C | At least one strict = Strict |
| A β₯ B | B > C | A > C | At least one strict = Strict |
| A = B | B > C | A > C | Equality carries forward |
| A = B | B = C | A = C | Equality is transitive |
4. Opposite Directions = No Conclusion
When inequalities point in opposite directions from a common element, you cannot combine them:
Think of it: A is bigger than B, and C is also bigger than B. But we don't know if A is bigger, smaller, or equal to C β they're both "above" B but could be anywhere.
Coded Symbols β Cracking the Secret Language
In competitive exams, inequality symbols are replaced with coded symbols (special characters, shapes, or letters). Your job: decode the symbols, form the inequality chain, and evaluate the conclusions. Let's master this systematically.
Standard Coding Scheme (Most Common in Exams)
While every exam can define its own codes, here are the most frequently used coding patterns across SBI PO, IBPS, and SSC exams:
π Code Set 1 β The Classic Banking Pattern
π Code Set 2 β Alternate Pattern (Also Common)
How to Read the Question
A typical exam question looks like this:
π Sample Question Format
Directions: In the following questions, the symbols Β©, Β£, @, %, and $ are used with the following meanings:
'P Β© Q' means 'P is greater than Q'
'P Β£ Q' means 'P is less than Q'
'P @ Q' means 'P is equal to Q'
'P % Q' means 'P is greater than or equal to Q'
'P $ Q' means 'P is less than or equal to Q'
Statement: A Β© B, B % C, C @ D
Conclusions:
I. A Β© D
II. D $ B
Answer choices:
(A) Only I follows (B) Only II follows (C) Both follow (D) Neither follows
Decoding Strategy β The 4-Step Method
Follow this exact sequence every time, and you'll solve any coded inequality in 20β30 seconds:
π The 4-Step Rapid Solving Method
Step 1 β DECODE: Replace every coded symbol with its standard math inequality. Write it on rough paper.
Step 2 β CHAIN: Combine all statements into one continuous chain. Arrange elements left-to-right with arrows flowing in the same direction if possible.
Step 3 β CHECK: For each conclusion, trace the path between the two elements in your chain. If the path flows in one direction β conclusion can be evaluated. If the path reverses direction β "can't be determined."
Step 4 β ANSWER: Mark the conclusion as "definitely true," "definitely false," or "can't be determined" and select the matching option.
Let's Apply the 4-Step Method β Live Demo
Given Codes: Β© means >, Β£ means <, @ means =, % means β₯, $ means β€
Statement: M Β© N, N % O, O @ P
Conclusions: I. M Β© P II. P $ N
Step 1 β DECODE:
Step 2 β CHAIN:
All arrows point left-to-right (descending). β Valid chain.
Step 3 β CHECK Conclusion I: M Β© P β M > P
Follow the chain: M > N β₯ O = P. Since M > N and N β₯ O = P, we get M > P. β Definitely true.
Step 3 β CHECK Conclusion II: P $ N β P β€ N
From chain: N β₯ O = P β N β₯ P β P β€ N. β Definitely true.
Step 4 β ANSWER: Both I and II follow β (C)
Chain Inequality Solving β Advanced Techniques
Rules for Building and Reading Chains
π Chain Building Rules
Rule 1 β Same direction, connect: If A > B and B > C, chain as A > B > C. Conclusion: A > C β
Rule 2 β Equality passes through: If A > B and B = C, chain as A > B = C. Conclusion: A > C β
Rule 3 β Mixed β₯ and >: If A β₯ B and B > C, then A > C β (the strict inequality wins when mixed in same direction)
Rule 4 β Opposite directions break the chain: If A > B and B < C, you get A > B < C. Relationship between A and C? β Can't determine
Rule 5 β Multiple paths: If two different paths exist between elements, check both. If even one gives a definite answer, use it.
Combining Result Table β Master Reference
| Left Relation | Right Relation | Combined | Can Conclude? |
|---|---|---|---|
| A > B | B > C | A > C | β Yes |
| A > B | B β₯ C | A > C | β Yes |
| A > B | B = C | A > C | β Yes |
| A β₯ B | B β₯ C | A β₯ C | β Yes |
| A β₯ B | B > C | A > C | β Yes |
| A β₯ B | B = C | A β₯ C | β Yes |
| A = B | B = C | A = C | β Yes |
| A = B | B > C | A > C | β Yes |
| A = B | B β₯ C | A β₯ C | β Yes |
| A > B | B < C | A ? C | β No β opposite directions |
| A < B | B > C | A ? C | β No β opposite directions |
| A β₯ B | B β€ C | A ? C | β No β opposite directions |
Complex Chain Example
Statements: A > B, B β₯ C, C = D, D < E, E β€ F
Now let's evaluate:
| Conclusion | Path | Result |
|---|---|---|
| A > D? | A > B β₯ C = D β A > D | β Definitely true |
| A > E? | A > B β₯ C = D < E β direction changes at D | β Can't determine |
| F > C? | F β₯ E > D = C β F β₯ E > C β F > C | β Definitely true |
| A > F? | Direction changes at D | β Can't determine |
| D < F? | D < E β€ F β D < F | β Definitely true |
Comparison of Roots of Quadratic Equations
The Concept
Some advanced coded inequality questions give you two quadratic equations and ask you to compare their roots. Here's the technique:
π Quadratic Root Comparison Method
Given: Two quadratic equations, e.g.,
Equation I: xΒ² β 7x + 12 = 0
Equation II: yΒ² β 9y + 20 = 0
Step 1: Solve both equations to find their roots.
Eq I: xΒ² β 7x + 12 = 0 β (x β 3)(x β 4) = 0 β x = 3 or x = 4
Eq II: yΒ² β 9y + 20 = 0 β (y β 4)(y β 5) = 0 β y = 4 or y = 5
Step 2: Compare all possible pairs of roots:
x = 3 vs y = 4 β x < y
x = 3 vs y = 5 β x < y
x = 4 vs y = 4 β x = y
x = 4 vs y = 5 β x < y
Step 3: Determine the relationship:
In all cases, x β€ y. So: x β€ y (i.e., y β₯ x)
Decision Rules for Root Comparison
| Scenario | All Pairs Show | Conclusion |
|---|---|---|
| All pairs: x < y | x is always less | x < y |
| All pairs: x < y or x = y | x is never greater | x β€ y |
| All pairs: x > y | x is always greater | x > y |
| All pairs: x > y or x = y | x is never less | x β₯ y |
| Mixed: some x > y, some x < y | No consistent pattern | Can't determine |
Quick Factorisation Tricks
For equations of the form xΒ² + bx + c = 0:
- If b and c are both positive β both roots are negative
- If b is negative and c is positive β both roots are positive
- If c is negative β roots have opposite signs
- Sum of roots = βb/a, Product of roots = c/a
Decision Framework β True, False, or Can't Determine
The Three Verdicts
βοΈ How to Decide: Definitely True / Definitely False / Can't Determine
β Definitely True: The conclusion follows directly from the chain with no ambiguity. The chain supports it in ALL possible scenarios.
Example: Chain says A > B > C. Conclusion: A > C β Definitely True
β Definitely False: The conclusion directly contradicts the chain. There is NO possible scenario where it can be true.
Example: Chain says A > B > C. Conclusion: C > A β Definitely False
β Can't Determine: The chain does not provide enough information. The conclusion might be true in some cases and false in others.
Example: Chain says A > B < C. Conclusion: A > C β Can't Determine (A could be 10, B = 3, C = 5 β A > C; or A = 4, B = 3, C = 100 β A < C)
Common Exam Answer Formats
| Option | Meaning |
|---|---|
| (A) Only Conclusion I follows | I is definitely true, II is not definitely true |
| (B) Only Conclusion II follows | II is definitely true, I is not definitely true |
| (C) Either I or II follows | I and II are complementary β at least one must be true |
| (D) Neither I nor II follows | Both are either false or can't be determined |
| (E) Both I and II follow | Both are definitely true |
The Tricky "Either-Or" Case
This is the most confusing option and catches even good students:
π When Does "Either I or II" Apply?
"Either I or II follows" is selected when:
- Neither conclusion is individually definite
- But the two conclusions are complementary β one of them MUST be true
- Typically happens when one says A > B and the other says A β€ B (or A β₯ B and A < B)
Example: Chain gives A β₯ B (A could be > or = to B)
Conclusion I: A > B β Not definite (could be equal)
Conclusion II: A = B β Not definite (could be greater)
But one of them MUST be true β Either I or II follows
Worked Examples β 15 Solved Problems
Using Code Set: Β© β > Β£ β < @ β = % β β₯ $ β β€
Example 1 β Basic Chain (Level: Easy)
Statement: A Β© B, B Β© C, C Β© D
Conclusions: I. A Β© D II. B Β© D
Decode:
Conclusion I: A > D β From chain: A > B > C > D β A > D β True
Conclusion II: B > D β From chain: B > C > D β B > D β True
Answer: (E) Both I and II follow
Example 2 β Chain with Equality (Level: Easy)
Statement: P % Q, Q @ R, R Β© S
Conclusions: I. P Β© S II. P % R
Decode:
Conclusion I: P > S β P β₯ Q = R > S β P > S (since β₯ followed by > in same direction gives >) β True
Conclusion II: P β₯ R β P β₯ Q = R β P β₯ R β True
Answer: (E) Both I and II follow
Example 3 β Broken Chain (Level: Easy)
Statement: J Β© K, K Β£ L, L Β© M
Conclusions: I. J Β© M II. L Β© J
Decode:
Conclusion I: J > M β Path: J > K < L > M β direction changes at K. β Can't determine
Conclusion II: L > J β Path: J > K < L β direction changes at K. β Can't determine
Answer: (D) Neither I nor II follows
Example 4 β β₯ and β€ Mix (Level: Medium)
Statement: A % B, B $ C, C @ D
Conclusions: I. A % D II. A Β© D
Decode:
Conclusion I: A β₯ D β Path: A β₯ B β€ C = D β direction changes at B (β₯ then β€). β Can't determine
Conclusion II: A > D β Same path, same break. β Can't determine
Are they complementary? No β both are indeterminate independently and not complementary (A could be >, =, or < D).
Answer: (D) Neither I nor II follows
Example 5 β Either-Or Scenario (Level: Medium)
Statement: H % I, I @ J, J % K
Conclusions: I. H Β© K II. H @ K
Decode:
Conclusion I: H > K β From chain: H β₯ I = J β₯ K β H β₯ K. So H > K is possible but not certain (H might equal K). β Not definite.
Conclusion II: H = K β H β₯ K means H might equal K, but might not. β Not definite.
But: H β₯ K means H is either > K or = K. One of these MUST be true. Conclusions I and II are complementary!
Answer: (C) Either I or II follows
Example 6 β Five-Element Chain (Level: Medium)
Statement: T $ U, U @ V, V % W, W Β© X
Conclusions: I. T Β£ W II. U Β© X
Decode:
Conclusion I: T < W β Path: T β€ U = V β₯ W β direction changes at V (ascending then descending). β Can't determine
Conclusion II: U > X β Path: U = V β₯ W > X β U β₯ W > X β U > X β True
Answer: (B) Only Conclusion II follows
Example 7 β Reversed Reading (Level: Medium)
Statement: D Β© E, F Β£ E, F @ G
Conclusions: I. D Β© G II. G Β£ E
Decode:
D > E, F < E, F = G
Rearrange by linking common elements: D > E > F = G (since F < E means E > F)
Conclusion I: D > G β D > E > F = G β D > G β True
Conclusion II: G < E β G = F < E β G < E β True
Answer: (E) Both I and II follow
Example 8 β Only One Follows (Level: Medium)
Statement: M Β© N, N % O, P Β£ O
Conclusions: I. M Β© P II. O @ M
Decode:
M > N, N β₯ O, P < O β Rearrange: M > N β₯ O > P
Conclusion I: M > P β M > N β₯ O > P β M > P β True
Conclusion II: O = M β From chain M > N β₯ O β M > O or M β₯ O but not M = O necessarily. Since M > N β₯ O, if N > O then M > O (strict). If N = O then M > N = O β M > O. Either way M > O. So O = M is β False.
Answer: (A) Only Conclusion I follows
Example 9 β Quadratic Root Comparison (Level: Hard)
Equation I: xΒ² β 5x + 6 = 0
Equation II: yΒ² β 7y + 10 = 0
Find the relationship between x and y.
Solve Eq I: xΒ² β 5x + 6 = 0 β (x β 2)(x β 3) = 0 β x = 2 or x = 3
Solve Eq II: yΒ² β 7y + 10 = 0 β (y β 2)(y β 5) = 0 β y = 2 or y = 5
Compare all pairs:
| x | y | Comparison |
|---|---|---|
| 2 | 2 | x = y |
| 2 | 5 | x < y |
| 3 | 2 | x > y |
| 3 | 5 | x < y |
Results are mixed (some <, some >, some =). Answer: Relationship cannot be established.
Example 10 β Quadratic with Clear Result (Level: Hard)
Equation I: xΒ² + 7x + 12 = 0
Equation II: yΒ² β 3y + 2 = 0
Solve Eq I: xΒ² + 7x + 12 = 0 β (x + 3)(x + 4) = 0 β x = β3 or x = β4
Solve Eq II: yΒ² β 3y + 2 = 0 β (y β 1)(y β 2) = 0 β y = 1 or y = 2
Compare all pairs:
| x | y | Comparison |
|---|---|---|
| β3 | 1 | x < y |
| β3 | 2 | x < y |
| β4 | 1 | x < y |
| β4 | 2 | x < y |
All pairs: x < y. Answer: x < y (i.e., y > x)
Example 11 β Six-Element Chain (Level: Hard)
Statement: A Β© B, B % C, C @ D, D Β£ E, E $ F
Conclusions: I. A Β© F II. F % C III. A Β© D
Decode:
Conclusion I: A > F β Path from A to F passes through D where direction changes (> then <). β Can't determine
Conclusion II: F β₯ C β F β₯ E > D = C β F β₯ E > C β F > C. Since F > C, then F β₯ C is also true. β True
Conclusion III: A > D β A > B β₯ C = D β A > D β True
Answer: Only II and III follow
Example 12 β Multiple Breaks (Level: Hard)
Statement: P Β£ Q, Q Β© R, R Β£ S, S Β© T
Conclusions: I. T Β© R II. Q Β© T
Decode:
Two break points: at Q (ascendingβdescending) and at S (ascendingβdescending).
Conclusion I: T > R β T is on the right side of S (S > T), R is on the left side of S (R < S). So R < S > T β direction change at S. β Can't determine
Conclusion II: Q > T β Q is left of R, T is right of S. Path: Q > R < S > T β multiple breaks. β Can't determine
Answer: (D) Neither I nor II follows
Example 13 β Quadratic with Negative Coefficient (Level: Hard)
Equation I: 2xΒ² + 5x β 3 = 0
Equation II: 2yΒ² β 7y + 3 = 0
Solve Eq I: 2xΒ² + 5x β 3 = 0 β 2xΒ² + 6x β x β 3 = 0 β 2x(x + 3) β 1(x + 3) = 0 β (2x β 1)(x + 3) = 0 β x = Β½ or x = β3
Solve Eq II: 2yΒ² β 7y + 3 = 0 β 2yΒ² β 6y β y + 3 = 0 β 2y(y β 3) β 1(y β 3) = 0 β (2y β 1)(y β 3) = 0 β y = Β½ or y = 3
Compare all pairs:
| x | y | Comparison |
|---|---|---|
| Β½ | Β½ | x = y |
| Β½ | 3 | x < y |
| β3 | Β½ | x < y |
| β3 | 3 | x < y |
All pairs: x β€ y (x is less than or equal to y in every case). Answer: x β€ y
Example 14 β Complementary Conclusions (Level: Medium)
Statement: W $ X, X @ Y, Y $ Z
Conclusions: I. W Β£ Z II. Z @ W
Decode:
Conclusion I: W < Z β From chain: W β€ X = Y β€ Z β W β€ Z. So W < Z is possible but not certain (W might equal Z). β Not definite.
Conclusion II: Z = W β Also possible but not certain. β Not definite.
Are they complementary? W β€ Z means W < Z or W = Z. Conclusions I (W < Z) and II (Z = W) cover both cases. One MUST be true.
Answer: (C) Either I or II follows
Example 15 β Mixed Codes with Alternate Symbols (Level: Hard)
Given Codes: β means >, β³ means <, β― means =, β means β₯, β‘ means β€
Statement: A β B, B β― C, C β D, D β‘ E, E β³ F
Conclusions: I. A β D II. F β C III. A β E
Decode:
Conclusion I: A > D β A β₯ B = C > D β A > D (since β₯ then = then > in same direction β strict >) β True
Conclusion II: F > C β C > D β€ E < F. Path from C to F: C > D β€ E < F β direction changes. β Can't determine
Conclusion III: A β₯ E β A β₯ B = C > D β€ E β direction change at D. β Can't determine
Answer: Only Conclusion I follows
MCQ Assessment Bank β 30 Questions (Bloom's Mapped)
Codes for Q1βQ24: Β© β > Β£ β < @ β = % β β₯ $ β β€
Remember / Recall (Q1βQ5)
If 'P Β© Q' means 'P is greater than Q', what does 'P Β£ Q' mean?
- P is greater than Q
- P is less than Q
- P is equal to Q
- P is not equal to Q
The symbol 'β₯' means:
- Strictly greater than
- Strictly less than
- Greater than or equal to
- Less than or equal to
If A > B and B > C, which property allows us to conclude A > C?
- Commutative property
- Transitive property
- Associative property
- Distributive property
In a quadratic equation axΒ² + bx + c = 0, the sum of roots is:
- b/a
- βb/a
- c/a
- βc/a
If A > B, then which of the following is the same statement written in reverse?
- A < B
- B > A
- B < A
- B = A
Understand / Explain (Q6βQ10)
Statement: A Β© B, B @ C. Which conclusion is true?
- A @ C (A = C)
- A Β© C (A > C)
- C Β© A (C > A)
- A Β£ C (A < C)
Why can't we determine the relationship between A and C if A > B and B < C?
- Because A and C are not in the same equation
- Because the inequality directions reverse at B, creating ambiguity
- Because B is an unknown variable
- Because we need a fourth variable
If X β₯ Y and Y > Z, what can we conclude about X and Z?
- X = Z
- X β₯ Z
- X > Z
- Cannot determine
What does "Either Conclusion I or II follows" mean in coded inequality questions?
- Both conclusions are true simultaneously
- Exactly one conclusion is true but we can't tell which, and they are complementary
- Both conclusions are false
- We need more data to decide
In quadratic root comparison, if Equation I gives x = β2, β5 and Equation II gives y = 1, 3, what is the relationship?
- x > y
- x < y
- x = y
- Cannot determine
Apply / Solve (Q11βQ15)
Statement: P Β© Q, Q % R, R @ S. Conclusions: I. P Β© S II. S $ Q
- Only I follows
- Only II follows
- Both follow
- Neither follows
Statement: A $ B, B @ C, C % D. Conclusions: I. A % D II. D $ A
- Only I follows
- Only II follows
- Both follow
- Neither follows
Statement: M Β© N, O Β£ N, O @ P. Conclusions: I. M Β© P II. N % P
- Only I follows
- Only II follows
- Both follow
- Neither follows
Statement: E % F, F Β© G, G $ H. Conclusions: I. E Β© H II. E Β© G
- Only I follows
- Only II follows
- Both follow
- Neither follows
Statement: J $ K, K @ L, L Β£ M, M Β© N. Conclusions: I. N Β£ L II. J Β£ M
- Only I follows
- Only II follows
- Both follow
- Neither follows
Analyse / Evaluate (Q16βQ20)
Statement: A Β© B, B % C, C $ D, D Β£ E. Conclusions: I. A Β© D II. E Β© C
- Only I follows
- Only II follows
- Both follow
- Neither follows
Statement: P % Q, Q @ R, R % S, S @ T. Conclusions: I. P Β© T II. P @ T
- Only I follows
- Only II follows
- Either I or II follows
- Neither follows
Statement: W Β© X, X Β£ Y, Y Β© Z. Conclusions: I. W Β© Z II. Y Β© W
- Only I follows
- Only II follows
- Both follow
- Neither follows
Statement: A % B, B $ C, C @ D, D Β© E. Conclusions: I. A % E II. C Β© E
- Only I follows
- Only II follows
- Both follow
- Neither follows
Statement: L @ M, M Β© N, N $ O, O @ P. Conclusions: I. L Β© P II. L $ P
- Only I follows
- Only II follows
- Either I or II follows
- Neither follows
Evaluate / Apply to Complex Scenarios (Q21βQ25)
Equation I: xΒ² β 8x + 15 = 0. Equation II: yΒ² β 5y + 6 = 0. What is the relationship between x and y?
- x > y
- x < y
- x β₯ y
- Cannot be determined
Equation I: xΒ² + x β 6 = 0. Equation II: yΒ² β y β 6 = 0. What is the relationship between x and y?
- x > y
- x < y
- x = y
- Cannot be determined
Statement: A Β© B, C $ B, C % D, E Β£ D. Conclusions: I. A Β© D II. E Β£ B
- Only I follows
- Only II follows
- Both follow
- Neither follows
Statement: M $ N, N Β© O, O % P, P @ Q. Conclusions: I. M Β£ P II. Q $ N
- Only I follows
- Only II follows
- Both follow
- Neither follows
Create / Advanced Problem Solving (Q25βQ30)
Equation I: 3xΒ² + 14x + 8 = 0. Equation II: 3yΒ² + 10y + 8 = 0. What is the relationship?
- x > y
- x < y
- x β€ y
- Cannot be determined
Statement: R Β© S, S $ T, T Β© U, U % V. Conclusions: I. R Β© V II. T Β© V
- Only I follows
- Only II follows
- Both follow
- Neither follows
Statement: A % B, B @ C, C % D, D @ E, E % F. Conclusions: I. A Β© F II. A @ F
- Only I follows
- Only II follows
- Either I or II follows
- Both follow
Equation I: xΒ² β 12x + 35 = 0. Equation II: yΒ² β 8y + 15 = 0. What is the relationship?
- x > y
- x β₯ y
- x < y
- Cannot be determined
Statement: G Β£ H, H % I, I Β© J, K $ J. Conclusions: I. G Β£ J II. K Β£ H
- Only I follows
- Only II follows
- Both follow
- Neither follows
Statement: P Β© Q, Q $ R, R Β© S, S % T, T @ U. Conclusions: I. P Β© U II. R Β© U
- Only I follows
- Only II follows
- Both follow
- Neither follows
Short Answer Questions β 8 Questions
Define the transitive property of inequalities. Give one example.
Explain the difference between '>' and 'β₯' with an example relevant to coded inequalities.
What happens when inequality directions reverse in a chain? Explain with an example.
Describe the 4-step method for solving coded inequality questions.
When does the "Either Conclusion I or II follows" option apply? Give a specific example.
How do you compare roots of two quadratic equations? List the steps.
If a chain shows A β₯ B β₯ C, can we conclude A > C? Justify.
In the quadratic equation xΒ² + bx + c = 0, how can you determine the signs of the roots without solving?
Long Answer Questions β 3 Questions
Given the following coded inequalities, decode, build the chain, and evaluate all three conclusions. Show complete working.
Codes: Β© β >, Β£ β <, @ β =, % β β₯, $ β β€
Statements: A Β© B, B % C, C @ D, D Β£ E, E $ F
Conclusions: I. A Β© D II. F % C III. A Β© F
Step 1 β Decode each statement:
β’ A Β© B β A > B
β’ B % C β B β₯ C
β’ C @ D β C = D
β’ D Β£ E β D < E
β’ E $ F β E β€ F
Step 2 β Build the chain:
A > B β₯ C = D < E β€ F
The chain has a direction change at D (descending from A to D, then ascending from D to F).
Step 3 β Evaluate each conclusion:
Conclusion I: A Β© D β A > D
Path: A > B β₯ C = D. All arrows point the same direction (left-to-right descending). A > B means A is greater than B. B β₯ C means B is at least C. C = D. Combining: A > B β₯ C = D β A > D. β
Conclusion I is DEFINITELY TRUE.
Conclusion II: F % C β F β₯ C
Path from F to C: F β₯ E > D = C (reading the chain from right to left: F β₯ E, E > D, D = C). So F β₯ E > D = C β F > D = C β F > C. Since F > C, then F β₯ C is also true (> is a subset of β₯). β
Conclusion II is DEFINITELY TRUE.
Conclusion III: A Β© F β A > F
Path: A > B β₯ C = D < E β€ F. The direction changes at D (from descending to ascending). We know A > D and F > D, but we cannot determine the relationship between A and F. A could be greater, less, or equal to F. β Conclusion III CANNOT BE DETERMINED.
Final Answer: Only Conclusions I and II follow.
Solve the following quadratic equations, compare the roots of both, and determine the relationship between x and y. Verify using the sign-based shortcut method.
Equation I: xΒ² + 9x + 20 = 0 Equation II: yΒ² β 11y + 28 = 0
Solving Equation I: xΒ² + 9x + 20 = 0
Find two numbers that multiply to 20 and add to 9: 4 Γ 5 = 20, 4 + 5 = 9.
Factorisation: (x + 4)(x + 5) = 0
Roots: x = β4 or x = β5
Solving Equation II: yΒ² β 11y + 28 = 0
Find two numbers that multiply to 28 and add to 11: 4 Γ 7 = 28, 4 + 7 = 11.
Factorisation: (y β 4)(y β 7) = 0
Roots: y = 4 or y = 7
Comparing all root pairs:
β’ x = β4 vs y = 4 β β4 < 4 β x < y
β’ x = β4 vs y = 7 β β4 < 7 β x < y
β’ x = β5 vs y = 4 β β5 < 4 β x < y
β’ x = β5 vs y = 7 β β5 < 7 β x < y
All four pairs show x < y. Conclusion: x < y (i.e., y > x).
Verification using sign-based shortcut:
Eq I: xΒ² + 9x + 20 = 0. Here b = +9, c = +20. Since b > 0 and c > 0, the sum of roots is negative (βb = β9) and product is positive (c = 20). Both roots must be negative. β (We got β4 and β5.)
Eq II: yΒ² β 11y + 28 = 0. Here b = β11, c = +28. Since b < 0 and c > 0, the sum of roots is positive (βb = 11) and product is positive (c = 28). Both roots must be positive. β (We got 4 and 7.)
Shortcut conclusion: All roots of Eq I are negative. All roots of Eq II are positive. Every negative number is less than every positive number. Therefore x < y β confirmed without individual pair comparison!
Explain the complete decision framework for coded inequality questions: when does a conclusion "definitely follow," when is it "definitely false," when "can't be determined," and when does the "either-or" case apply? Illustrate each case with a unique example.
The decision framework for coded inequality questions involves four possible verdicts for any conclusion:
Case 1 β Definitely Follows (True):
A conclusion definitely follows when the chain inequality directly supports it with no ambiguity. The path between the two elements in the conclusion must flow in one consistent direction.
Example: Chain: A > B > C > D. Conclusion: A > D.
The path A β B β C β D flows consistently downward. A > D in every possible scenario. β
Definitely follows.
Case 2 β Definitely False:
A conclusion is definitely false when it directly contradicts the chain. The chain proves the opposite with certainty.
Example: Chain: A > B > C. Conclusion: C > A.
The chain proves A > C. The opposite (C > A) is impossible. β Definitely false.
Case 3 β Can't Be Determined:
When the path between two elements involves a direction reversal, the chain doesn't provide enough information. The conclusion might be true in some scenarios and false in others.
Example: Chain: A > B < C. Conclusion: A > C.
Scenario 1: A=10, B=3, C=5 β A > C (true). Scenario 2: A=4, B=3, C=100 β A < C (false). The direction reversal at B makes the A-C relationship indeterminate. β Can't determine.
Case 4 β Either-Or:
This special case applies when TWO conclusions are individually indeterminate, but they are logically complementary β one of them MUST be true. This typically occurs when the chain gives a non-strict inequality (β₯ or β€), and the two conclusions split it into its strict and equality components.
Example: Chain: P β₯ Q (from P β₯ R = Q). Conclusion I: P > Q. Conclusion II: P = Q.
Neither is individually certain (P could be greater or equal). But P β₯ Q means exactly one of {P > Q, P = Q} must be true. They are exhaustive and mutually exclusive. β Either I or II follows.
Important notes for exam application:
1. Always check for "either-or" last β after confirming neither conclusion individually follows.
2. Two conclusions are complementary only if they cover all possibilities without overlap (e.g., > and =, or < and β₯).
3. "A > B" and "A < B" are NOT complementary because "A = B" is missing β use either-or only for complete partitions like > vs β€, or < vs β₯, or > vs = when the chain gives β₯.
4. In exam marking: if you select "Neither" when the answer is "Either," you lose marks. This is the most commonly lost mark in banking exams on this topic.
Chapter Summary β Quick Revision Card
π― Unit 7 β Coded Inequalities: Key Takeaways
1. Six Symbols: > (greater), < (less), β₯ (greater or equal), β€ (less or equal), = (equal), β (not equal).
2. Coded Symbols: Exams replace standard symbols with codes (Β©, Β£, @, %, $, β , β³, etc.). Always read the code table FIRST.
3. The 4-Step Method: DECODE β CHAIN β CHECK β ANSWER. Follow this for every question.
4. Chain Rule: Same direction = can combine. Direction reversal = chain breaks, can't determine.
5. Combining Rules: Strict + Strict = Strict. Non-strict + Non-strict = Non-strict. Strict + Non-strict (same dir) = Strict. Equality passes through.
6. Quadratic Roots: Solve both equations, compare ALL four root pairs. Consistent result = definite answer. Mixed results = can't determine. Use sign shortcut for speed.
7. Three Verdicts: Definitely True (chain supports), Definitely False (chain contradicts), Can't Determine (chain has direction break).
8. Either-Or: When neither conclusion alone is certain, but they are complementary (one MUST be true). Common with β₯ split into > and =.
9. Exam Strategy: 5 questions guaranteed in banking exams. Target: all 5 correct in under 2 minutes. This is the easiest scoring section.
| Concept | Difficulty | Exam Frequency | Mastery Check |
|---|---|---|---|
| Basic inequality symbols | Easy | Every exam (foundation) | β Can list all 6 symbols with meanings |
| Symbol decoding | Easy | Every question | β Can decode any code table in 10 seconds |
| Chain building | Medium | Every question | β Can build chains with 4β6 elements |
| Direction-break detection | Medium | 70% of questions | β Can spot breaks instantly |
| Either-Or identification | Hard | 20% of questions | β Can identify complementary conclusions |
| Quadratic root comparison | Hard | Bank Mains exams | β Can solve and compare in 45 seconds |
| Sign-based shortcuts | Advanced | Mains level | β Can determine root signs without solving |
β Unit 7 complete. You are now ready to tackle Coded Inequalities in any competitive exam!
[QR: Link to EduArtha practice set β Coded Inequalities]