Aptitude Topics
Percentage Increase & Decrease
Percentage change measures the relative difference between an old value and a new value.
Fundamental Principles
Percentage Increase
The amount of increase divided by the original value, multiplied by 100.
Percentage Decrease
The amount of decrease divided by the original value, multiplied by 100.
Essential Formulation Tips
- The denominator in your formula must always be the original value, not the new value.
Shortcut Execution Techniques
- To increase a value by x%, multiply it by (1 + x/100). To decrease it, multiply by (1 - x/100).
Contextual Inquiries (FAQs)
Q: Can a percentage decrease be greater than 100%?
A:
Example Breakdown: Calculating a Price Drop
Standard problem style for discount pricing systems.Problem QueryA shirt price drops from $80 to $60. Find the percentage decrease.
Step-By-Step Solution Path
Change = 80 - 60 = 20
Percentage Decrease = (Change / Original Value) × 100
= (20 / 80) × 100 = 25%
Analytical Hint: Identify the original price as the base value.
Increase & Decrease Practice Set 1
Problems focused on tracking shifting margins.
Q1. A commodity's price increases from $50 to $65. What is the percentage increase?