ZE
ZESTEXAM

RRB ALP Percentage Change

Study Material — 15 PYQs (2018–2023) · Concept Notes · Shortcuts

RRB ALP Percentage Change is a frequently tested subtopic — 15 previous year questions from 2018–2023 papers are included below with concept notes, key rules and shortcut tricks.

15 PYQs
2018–2023
34 Practice
MCQs
10 Key Points
to remember
Free
no login needed
Take Free Mock →Full Practice Set
Also for:NTPCGroup DJETech
PYQs
15
Practice
34
Key Points
10
Access
Free
Previous Year Questions

RRB ALP Percentage Change — Past Exam Questions

15 questions from actual RRB ALP papers · all shown free · click option to reveal solution

Exam Q 12023Previous Year Pattern

The number of employees in a company increased from 400 to 500. What is the percentage increase in the number of employees?

Exam Q 22023Previous Year Pattern

The price of a book increased from ₹200 to ₹250. What is the percentage increase in price?

Exam Q 32023Previous Year Pattern

The population of a town increased from 50,000 to 60,000. What is the percentage increase in population?

Exam Q 42023Previous Year Pattern

A mobile phone's price decreased from ₹15,000 to ₹12,000. What is the percentage decrease in price?

Exam Q 52023Previous Year Pattern

The population of a town was 50,000 in 2020. If it increased by 20% in 2021, what was the population in 2021?

Exam Q 62023Previous Year Pattern

A student's marks increased from 60 to 75. What is the percentage increase in marks?

Exam Q 72023Previous Year Pattern

A student scored 72 marks out of 120 in an exam. What is the percentage of marks obtained?

Exam Q 82020Previous Year Pattern

The price of a commodity increases by 25% in the first year. In the second year, the price decreases by 20% from the increased price. What is the net percentage change in the price over the two years?

Exam Q 92023Previous Year Pattern

A shopkeeper reduced the price of a shirt from ₹800 to ₹600. What is the percentage decrease?

Exam Q 102018Previous Year Pattern

The price of a shirt increased from ₹400 to ₹500. What is the percentage increase in the price?

Exam Q 112023Previous Year Pattern

A shopkeeper buys goods at ₹800 per unit. He marks up the price by 40% and then offers a discount of 15% on the marked price. What is the profit percentage?

Exam Q 122023Previous Year Pattern

The price of a commodity increases by 25% in the first year and then decreases by 20% in the second year. What is the net percentage change in price over the two years?

Exam Q 132018Previous Year Pattern

The price of a laptop was increased by 20% and then decreased by 15%. What is the net percentage change in the price of the laptop?

Exam Q 142020Previous Year Pattern

The price of a commodity increases by 25% in the first year. In the second year, the new price decreases by 20%. If the final price is ₹600, what was the original price?

Exam Q 152020Previous Year Pattern

The price of a commodity increases by 25% in the first year. In the second year, it decreases by 20% of the new price. In the third year, it increases by 10% of the price at the end of the second year. If the final price is ₹1,980, what was the original price?

Concept Notes

Percentage Change— Rules & Concept

Core ConceptRead this first — the foundation of the topic

Percentage change is the difference between the original value and the new value, expressed as a percentage of the original value. This concept appears in almost every SSC CGL paper and forms the backbone of profit-loss, simple interest, and data interpretation questions. Core Concept: When any quantity increases or decreases, we calculate the percentage change to measure the rate of change. For example, if your salary increases from Rs 20,000 to Rs 25,000, the percentage increase is 25%.

Formula BlockMemorise — at least one formula appears in every paper

Block:

• Percentage Increase = [(New Value - Original Value) / Original Value] × 100
• Percentage Decrease = [(Original Value - New Value) / Original Value] × 100
• New Value after x% increase = Original Value × (100 + x)/100
• New Value after x% decrease = Original Value × (100 - x)/100
• Successive percentage changes: If a value changes by a% then b%, final change = [a + b + (ab/100)]%
Exam PatternsWhat examiners ask — read before attempting PYQs

SSC loves asking percentage change in population growth, salary hikes, price fluctuations, and successive discounts. Questions often involve finding original values when final values and percentage changes are given.

ShortcutsUse these to save 30–60 seconds per question
1

Two successive increases of x% = (x + x + x²/100)% total increase

2

One increase of x% followed by decrease of x% = (x²/100)% net decrease

3

25% increase means multiply by 1.25

4

20% decrease means multiply by 0.8

5

12.5% increase means multiply by 9/8

Worked ExampleSolve this step-by-step before moving on
1
Step 1

Identify original value = 50,000, new value = 65,000

2
Step 2

Find increase = 65,000 - 50,000 = 15,000

3
Step 3

Apply formula = (15,000/50,000) × 100 = 30% Answer: 30% increase Worked Example 2: A number is first increased by 20% and then decreased by 15%. Find the overall percentage change.

1
Step 1

Let original number = 100 (always take 100 for easier calculation)

2
Step 2

After 20% increase = 100 × 1.2 = 120

3
Step 3

After 15% decrease = 120 × 0.85 = 102

4
Step 4

Overall change = 102 - 100 = 2

5
Step 5

Percentage change = 2% increase Alternative: Using formula = 20 + (-15) + (20×(-15)/100) = 20 - 15 - 3 = 2% increase Shortcut Trick #3: Percentage to fraction conversions: • 12.5% = 1/8, 16.67% = 1/6, 33.33% = 1/3, 66.67% = 2/3 • These help in quick mental calculations during exams.

Exam TrapsCommon mistakes students make — avoid these

#1: Students often confuse which value to use as base. Remember: percentage change is always calculated on the ORIGINAL value, not the new value. If price changes from Rs 100 to Rs 120, the base is Rs 100, not Rs 120.

Many students calculate (20/120) × 100 instead of (20/100) × 100, leading to wrong answers. Exam Strategy: Practice reverse calculations where you find original values from final values and percentage changes. SSC frequently tests this concept in tricky word problems involving multiple successive changes.

Key Points to Remember

  • Percentage change = [(New Value - Original Value) / Original Value] × 100
  • Always use original value as denominator, never the new value
  • Successive changes formula: a + b + (ab/100) for changes of a% and b%
  • Quick multipliers: 25% increase = ×1.25, 20% decrease = ×0.8
  • Two successive changes of x% each = x + x + x²/100 total change
  • Increase followed by same % decrease gives net decrease of x²/100
  • 12.5% = 1/8, 16.67% = 1/6, 33.33% = 1/3 for quick calculations
  • Population, salary, price problems are most common question types
  • Practice finding original values when final value and change% are given
  • Take original value as 100 for easier calculation in successive changes

Exam-Specific Tips

  • 12.5% equals exactly 1/8 fraction
  • 16.67% equals exactly 1/6 fraction
  • 33.33% equals exactly 1/3 fraction
  • 66.67% equals exactly 2/3 fraction
  • Successive 10% increases give 21% total increase
  • 10% increase followed by 10% decrease gives 1% net decrease
  • 25% increase followed by 20% decrease gives 0% net change
  • Two successive 50% increases give 125% total increase
Practice MCQs

Percentage Change — Practice Questions

34graded MCQs · easy to hard · full solution & trap analysis · showing 20 of 34

All MCQs →
Practice 1easy

The salary of an employee was ₹30,000 per month. It was increased by 15%. What is the new salary?

Practice 2easy

The price of a commodity increases by 25% in the first month and then decreases by 20% in the second month. What is the net percentage change in the price over the two months?

Practice 3easy

A student scored 72 marks out of 120 in an exam. What is the percentage of marks obtained?

Practice 4easy

A shopkeeper reduced the price of a shirt from ₹800 to ₹600. What is the percentage decrease?

Practice 5easy

The population of a village decreased from 5000 to 4500. What is the percentage decrease in population?

Practice 6easy

A student's marks increased from 60 to 75. What is the percentage increase in marks?

Practice 7easy

If the population of a town was 50,000 and it increased by 20%, what is the new population?

Practice 8easy

The price of a book increased from ₹200 to ₹250. What is the percentage increase in price?

Practice 9easy

A shopkeeper reduced the price of a shirt from ₹800 to ₹600. What is the percentage decrease in price?

Practice 10easy

The price of petrol decreased from ₹100 per litre to ₹80 per litre. What is the percentage decrease?

Practice 11medium

A shopkeeper marks up goods by 60% above cost price. He then offers a discount of 25% on the marked price. What is his profit percentage?

Practice 12medium

The population of a town increases by 10% in the first year. In the second year, it decreases by 5%. In the third year, it increases by 8%. What is the net percentage change in population after three years?

Practice 13medium

A shopkeeper buys goods at ₹500 per unit. He marks up the price by 40% but then offers a discount of 10% on the marked price. What is his profit percentage?

Practice 14medium

A student's marks increased from 45 to 54. Later, the marks were recalculated and decreased from 54 to 48. What is the net percentage change in marks from the original value of 45?

Practice 15medium

The value of a car depreciates by 15% in the first year and 10% in the second year. If the initial value was ₹5,00,000, what is the value after two years?

Practice 16medium

The price of a commodity increases by 25% in the first year and then decreases by 20% in the second year. What is the net percentage change in price over the two years?

Practice 17medium

The value of a car depreciates by 20% in the first year and 15% in the second year. If the initial value was ₹5,00,000, what is the value after two years?

Practice 18medium

A shopkeeper marks up goods by 40% above cost price. He then offers a discount of 25% on the marked price. What is his profit percentage?

Practice 19medium

The price of a commodity increases by 25% in the first year. In the second year, it decreases by 20% of the new price. If the original price was ₹800, what is the percentage change in price over the two years?

Practice 20medium

A number is increased by 50% and then decreased by 50%. What is the net percentage change?

14 more practice questions in the Study Panel

Difficulty-graded, bookmarkable, with timed mode. Free account — no credit card.

Create Free Account →Browse Questions

60-Second Revision — Percentage Change

  • Formula: Percentage change = [(New - Original) / Original] × 100
  • Remember: Original value is always the base for calculation
  • Successive changes: a + b + (ab/100) for a% then b% change
  • Trap: Never use new value as denominator in percentage change
  • Quick trick: Take original as 100 for successive change problems
  • Memorize: 12.5%=1/8, 16.67%=1/6, 33.33%=1/3, 25%=1/4
  • Practice: Finding original values from final values and percentages
Studied the notes? Now test yourself
See how Percentage Change appears in the real RRB ALP paper
Full timed mock · Instant All-India percentile · Free
Free forever for basic prepNo app downloadReal exam-pattern questions12,000+ aspirants
Test Percentage Change under exam conditions
Free RRB ALP mock · instant rank · no login
Free Mock →