Absolute Values

Absolute Values Data Sufficiency problems test your ability to determine if given statements provide enough information about modulus equations or inequalities. You must assess sufficiency using the definition |x| = distance from zero, considering both positive and negative cases.

10Worksheets
200+Practice Questions
HardDifficulty
2-3 hoursHours to Master

Introduction to Absolute Values

Absolute Values Data Sufficiency problems test your ability to determine if given statements provide enough information about modulus equations or inequalities. You must assess sufficiency using the definition |x| = distance from zero, considering both positive and negative cases.

Prerequisites

Absolute value definition: |x| = x if x≥0, -x if x<0 |x| = a means x = a or x = -a |x| < a means -a < x < a |x| > a means x < -a or x > a
Why This Matters: Absolute Values appear in 1-2 questions in CAT and GMAT exams. They test modulus reasoning and sufficiency analysis.

How to Solve Absolute Values Problems

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Step 1: Identify what is being asked (value of x, range of x, etc.)

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Step 2: Translate each statement into absolute value conditions

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Step 3: Check if Statement (1) alone gives a unique answer

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Step 4: Check if Statement (2) alone gives a unique answer

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Step 5: Combine statements if needed

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Step 6: Consider both positive and negative cases for absolute value equations

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Step 7: Select the appropriate DS answer choice

Pro Strategy: Absolute value equations yield two solutions (positive and negative) unless additional constraints (x>0, x<0, integer, range) narrow to one.

Example Problem

Example: What is the value of x? Statement (1): |x| = 5 Statement (2): x² = 25 and x > 0 Solution: Step 1: Question asks for value of x Step 2: Statement (1): |x| = 5 → x = 5 or x = -5 → NOT sufficient alone (two values) Step 3: Statement (2): x² = 25 → x = 5 or x = -5, but x > 0 → x = 5 → SUFFICIENT alone Answer: Statement (2) alone is sufficient

Pro Tips & Tricks

  • |x| = a (a>0) → x = a or x = -a (two solutions)
  • |x| = 0 → x = 0 (one solution)
  • |x| = a (a<0) → no solution
  • |x| < a → -a < x < a
  • |x| > a → x < -a or x > a
  • |x - k| = a → x = k ± a (two solutions)

Shortcut Methods to Solve Faster

|x| = a ↔ x = ±a
|x| < a ↔ -a < x < a
|x| > a ↔ x < -a or x > a
|x - k| = a ↔ x = k ± a
|x| = |y| ↔ x = ±y

Common Mistakes to Avoid

Assuming |x| = a gives a unique solution (forgets negative case)
Misapplying inequality direction for absolute value
Forgetting that |x| is always non-negative
Not considering that |x| = |y| gives two possibilities (x=y or x=-y)

Exam Importance

Absolute Values is an important topic for various competitive exams. Here's how frequently it appears:

CAT
1-2 questions
GMAT
1-2 questions
BANKING PO
1-2 questions
SSC CGL
1-2 questions
INSURANCE
1-2 questions

Ready to Master Absolute Values?

Start with Worksheet 1 and work your way up to expert level! Each worksheet includes:

20 practice questions
Detailed solutions
Step-by-step explanations
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