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15 Percentages Questions and Answers
15 solved Percentages questions with step-by-step explanations. Includes formulas, shortcuts, and tips for placement tests and competitive exams.
Percentages are one of the most frequently tested topics in placement aptitude rounds, competitive exams, and banking tests. A percentage represents a number as a fraction of 100 — denoted by the % symbol. The core skill tested is the ability to quickly convert between percentages, fractions, and decimals. Common question types include: finding a percentage of a given number, calculating percentage increase or decrease, reverse percentage problems (finding the original value after a change), and discount/markup problems involving marked price and selling price. Mastering percentage shortcuts — like knowing that 25% equals one-fourth, 50% equals half, and 10% equals one-tenth — can save valuable time in timed tests. Below are 15 solved percentage questions with detailed explanations to help you build speed and accuracy.
A quantity 300 is increased by 20%. What is the new value?
What is 15% of 240?
A quantity 660 is increased by 25%. What is the new value?
What is 25% of 680?
A quantity 320 is increased by 20%. What is the new value?
After a discount of 10%, the value changes from 1100 to what?
A quantity 220 is increased by 15%. What is the new value?
After a discount of 5%, the value changes from 820 to what?
What is 10% of 520?
A quantity 1100 is increased by 30%. What is the new value?
After a discount of 25%, the value changes from 220 to what?
A quantity 880 is increased by 30%. What is the new value?
After a discount of 25%, the value changes from 940 to what?
A quantity 1120 is increased by 15%. What is the new value?
After a discount of 20%, the value changes from 740 to what?
Key Takeaways
- Convert percentages to fractions for faster mental math: 25% = 1/4, 20% = 1/5, 10% = 1/10.
- For increase: multiply by (100 + p)/100. For decrease: multiply by (100 - p)/100.
- To find original after a change: divide the final value by (100 ± p)/100.
- Discount is always calculated on Marked Price, not Cost Price.
- Successive percentage change uses the formula: Net% = a + b + ab/100.
Frequently Asked Questions
What is the formula for percentage?
Percentage = (Value ÷ Total) × 100. For example, to find what percentage 30 is of 150: (30 ÷ 150) × 100 = 20%.
How do I calculate percentage increase?
Percentage increase = (New Value - Original Value) ÷ Original Value × 100. If a product increases from Rs. 200 to Rs. 250: Increase = 50, Percentage increase = (50 ÷ 200) × 100 = 25%.
How do I calculate percentage decrease?
Percentage decrease = (Original Value - New Value) ÷ Original Value × 100. For example, if a price drops from Rs. 500 to Rs. 400: Decrease = 100, Percentage decrease = (100 ÷ 500) × 100 = 20%.
What is the shortcut for 10%, 25%, and 50%?
10% = divide by 10. 25% = divide by 4 (one-fourth). 50% = divide by 2 (half). 20% = divide by 5. Use these fraction equivalents instead of always calculating (X ÷ 100) to save time.
How do I find the original amount after a percentage change?
If final value = Original × (100 ± p) ÷ 100, then Original = Final × 100 ÷ (100 ± p). For example, if Rs. 880 is the price after a 10% increase: Original = 880 × 100 ÷ 110 = Rs. 800.
What is successive percentage change?
When two percentage changes happen one after another, use: Net change = a + b + (a × b) ÷ 100. For increases of 10% followed by 20%: Net = 10 + 20 + (10 × 20) ÷ 100 = 32% increase. For decreases, use negative values.
More Percentages Practice Resources
For more percentages practice, try our timed quiz mode that generates fresh questions every session.