Introduction
In this pattern, two quantities are compared to determine which is greater, smaller, or equal. You are not asked to compute exact values - only to decide whether the given data is sufficient to establish the comparison.
Pattern: Comparison Type (Greater / Smaller)
Pattern
Key concept - Determine whether the given statements can conclusively show if A > B, A < B, or A = B.
Each statement may present equations, ratios, or relations. You must test whether these are enough to establish a clear comparison between A and B.
Step-by-Step Example
Question
Which is greater - A or B?
(I) A = B + 3
(II) A² = B² + 9
Solution
-
Step 1: Analyze Statement (I)
From (I): A = B + 3 ⇒ A - B = 3 → a positive constant.
Hence, A is always greater than B regardless of sign or value of B.
✅ (I) alone is sufficient. -
Step 2: Analyze Statement (II)
From (II): A² = B² + 9 ⇒ A² - B² = 9 ⇒ (A - B)(A + B) = 9.
The result depends on the specific values of A and B (for example, A - B could be 9 or 3 or even -9, depending on A + B).
So, (II) alone is ambiguous. ❌ Insufficient. -
Step 3: Combine
Even when both are combined, (I) alone already gives a definite result; (II) adds nothing new. -
Final Answer:
Only (I) is sufficient -
Quick Check:
(I) → A - B = 3 → A > B always ✅
(II) → multiple possible cases ❌
Quick Variations
1. Comparison using differences (A - B = constant).
2. Comparison using ratios (A/B = k), which may depend on sign of B.
3. Comparison using squares or absolute values often leads to ambiguity unless sign information is provided.
Trick to Always Use
- Step 1: Express A - B if possible - check whether it’s always positive or negative.
- Step 2: Watch for sign ambiguity when equations involve A², |A|, or ratios.
- Step 3: If sign of one variable affects the result, that statement is not sufficient.
Summary
Summary
- A statement is sufficient only if it always establishes A > B, A < B, or A = B.
- Any case-dependent result (depending on sign or value) means insufficiency.
- Check both statements independently, then together if needed.
- Equations with squares or absolute values frequently lose direction - handle carefully.
Example to remember:
(I) A = B + 3 → A > B always (sufficient).
(II) A² = B² + 9 → ambiguous (insufficient).
