Inequality
Here is a detailed explanation of the Inequality Reasoning content from your PDF, including core concepts, solved examples, and additional practice questions with explanations123.
Detailed Explanation of Inequality Reasoning
Inequality Reasoning involves comparing two or more elements using symbols such as $>$, $<$, $=$, $\geq$, $\leq$, and $\neq$. The goal is to deduce definite relationships between elements based on the given statements and to evaluate the validity of the conclusions drawn from them.
Key Concepts and Symbols
Symbol | Meaning |
---|---|
$A > B$ | A is greater than B |
$A < B$ | A is smaller than B |
$A = B$ | A is equal to B |
$A \geq B$ | A is greater than or equal to B |
$A \leq B$ | A is less than or equal to B |
$A \neq B$ | A is not equal to B |
$A \not \leq B$ | A is greater than B |
$A \not < B$ | A is greater than or equal to B |
How to Solve Inequality Questions
- Combine Statements: Write all inequalities in a single chain if possible.
- Analyze Relationships: Check if a direct relationship can be established between the elements in the conclusions.
- Evaluate Conclusions: For each conclusion, see if it logically follows from the combined statements.
- Special Cases:
- Either-Or Case: If two conclusions form a complementary pair (e.g., $A > B$ and $A \leq B$), and both are individually false, then “either-or” is true.
- No Direct Relationship: If you cannot establish a definite relationship, the conclusion is invalid.
Solved Examples
Example 1: Direct Inequality
Statement: $H < A < T = G > U \geq V \geq B$
Conclusions: I. $T > B$ II. $G > H$
Solution:
- Combine: $H < A < T = G > U \geq V \geq B$
- Conclusion I: $T > B$ is true because $T = G > U \geq V \geq B$
- Conclusion II: $G > H$ is true because $H < A < T = G$
- Answer: Both conclusions I and II follow.
Example 2: No Direct Relationship
Statement: $F > Y \geq X < Z$, $C \leq X < W$
Conclusions: I. $Z > C$ II. $F > W$
Solution:
- Combine: $F > Y \geq X \geq C$ and $F > Y \geq X < W$
- Conclusion I: $Z > C$ is true because $X \geq C$ and $X < Z$, so $Z > X \geq C$
- Conclusion II: $F > W$ is false because $F > Y \geq X < W$ does not establish a relationship between $F$ and $W$
- Answer: Only conclusion I follows.
Example 3: Either-Or Case
Statement: $B = K \geq H = T > U \leq I$
Conclusions: I. $H > I$ II. $H \leq I$
Solution:
- Combine: $B = K \geq H = T > U \leq I$
- Conclusion I: $H > I$ is false because $H = T > U \leq I$ does not mean $H > I$
- Conclusion II: $H \leq I$ is false because $H = T > U \leq I$ does not mean $H \leq I$
- But: Both conclusions are complementary and both are false individually, so “either-or” is true.
- Answer: Either conclusion I or II follows.
Example 4: Coded Inequality
Symbols:
- $A @ B$: $A \leq B$
- $A # B$: $A \geq B$
- $$ A \$ B$: $A = B $$
- $A % B$: $A < B$
- $A * B$: $A > B$
Statements:
$$ R \$ J; J \% Y; C @ Y $$Conclusions: I. $C % J$ II. $R * Y$ III. $R * C$
Solution:
- Decode: $R = J; J < Y; C \leq Y$
- Combine: $R = J < Y \geq C$
- Conclusion I: $C < J$ is false (no direct relation)
- Conclusion II: $R > Y$ is false ($R = J < Y$
- Conclusion III: $R > C$ is false (no direct relation)
- Answer: None follows.
Practice Questions
Question 1
Statements: $W < X; X \geq Y; Y = Z; Z \geq A$
Conclusions: I. $X \geq A$ II. $A < Z$ III. $A > X$
Solution:
- Combine: $W < X \geq Y = Z \geq A$
- I: $X \geq A$ is true.
- II: $A < Z$ is possible but not definite.
- III: $A > X$ is false.
- Answer: Only I is true.
Question 2
Statements: $P \geq U; Q \geq S; S \leq P; R \geq U$
Conclusions: I. $P \geq R$ II. $Q \leq U$ III. $S \geq R$
Solution:
- Combine: $Q \geq S \leq P \geq U \leq R$
- I: $P \geq R$ is false (no direct relation)
- II: $Q \leq U$ is false (no direct relation)
- III: $S \geq R$ is false (no direct relation)
- Answer: None is true.
Question 3
Statements: $A \leq B = D \leq E; F < L = K; E \geq F$
Conclusions: I. $F \geq B$ II. $E \geq A$
Solution:
- Combine: $A \leq B = D \leq E \geq F < L = K$
- I: $F \geq B$ is false (no direct relation)
- II: $E \geq A$ is true
- Answer: Only II is true.
Question 4
Statements: $X = Y > Z \leq A; A = Q; Q > R \geq S < W$
Conclusions: I. $W > R$ II. $A \geq Y$ III. $Q \geq Z$ IV. $Q \geq X$
Solution:
- Combine: $X = Y > Z \leq A = Q > R \geq S < W$
- I: $W > R$ is false (no direct relation)
- II: $A \geq Y$ is false (no direct relation)
- III: $Q \geq Z$ is true
- IV: $Q \geq X$ is false (no direct relation)
- Answer: Only III is true.
Tips for Solving Inequality Questions
- Always combine all statements if possible.
- Look for direct relationships between elements in the conclusions.
- Be cautious about “either-or” cases where both conclusions are individually false but together cover all possibilities.
- Practice with both direct and coded inequalities.
Summary Table
Question Type | Key Point | Example Answer |
---|---|---|
Direct Inequality | Combine and check direct relationships | Both I and II follow |
No Direct Relation | “Can’t say” if no direct relation | Only I follows |
Either-Or Case | Both conclusions are complementary | Either I or II follows |
Coded Inequality | Decode symbols, then proceed as above | None follows |
This comprehensive guide, with explanations, examples, and practice questions, will help you master inequality reasoning for any competitive exam123.