Study Material — 17 PYQs (2020–2020) · Concept Notes · Shortcuts
SBI PO Percentage Change is a frequently tested subtopic — 17 previous year questions from 2020–2020 papers are included below with concept notes, key rules and shortcut tricks.
17 questions from actual SBI PO papers · all shown free · click option to reveal solution
Exam Q 12020Previous Year Pattern
A company's revenue decreased from ₹5,00,000 to ₹4,00,000. What is the percentage decrease in revenue?
Exam Q 22020Previous Year Pattern
The cost of a laptop was ₹40,000. After a discount, it was sold for ₹32,000. What is the percentage discount offered?
Exam Q 32020Previous Year Pattern
A shopkeeper reduced the price of a shirt from ₹800 to ₹600. What is the percentage decrease in price?
Exam Q 42020Previous Year Pattern
A student scored 72 marks out of 120 in an exam. What is the percentage of marks obtained?
Exam Q 52020Previous Year Pattern
The population of a town increased from 50,000 to 60,000 in one year. What is the percentage increase in population?
Exam Q 62020Previous Year Pattern
The price of a mobile phone increased from ₹15,000 to ₹18,000. What is the percentage increase in price?
Exam Q 72020Previous Year Pattern
The salary of an employee is increased by 20% in January and then by 10% in July. If his salary in July (after the increase) was ₹66,000, what was his original salary in January (before any increase)?
Exam Q 82020Previous 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 92020Previous Year Pattern
The population of a city was 500,000 in 2020. It increased by 10% in 2021 and by 15% in 2022. What was the population in 2022?
Exam Q 102020Previous Year Pattern
A student scored 60% marks in an exam. If the total marks were increased from 100 to 150, and the student's marks are adjusted proportionally, what percentage of marks does the student now have?
Exam Q 112020Previous Year Pattern
A shopkeeper increases the cost price of an item by 40% to set the marked price. He then offers a discount of 25% on the marked price. What is his profit or loss percentage?
Exam Q 122020Previous Year Pattern
A population increased by 15% in Year 1, decreased by 10% in Year 2, and increased by 20% in Year 3. If the population at the end of Year 3 is 15,66,000, what was the initial population?
Exam Q 132020Previous Year Pattern
A merchant buys goods at ₹5,000 per unit. He marks them up by 50%, then offers a 10% discount on the marked price. Later, he offers an additional 5% discount on the already-discounted price. What is his overall profit percentage?
Exam Q 142020Previous Year Pattern
A product's price increased by 25% in the first quarter and then decreased by 20% in the second quarter. If the final price is ₹2,400, what was the original price?
Exam Q 152020Previous Year Pattern
A shopkeeper marks up goods by 60% above cost price. He then offers a discount of 25% on the marked price. If he earns a profit of ₹480 on a single item, what is the cost price?
Exam Q 162020Previous Year Pattern
A company's revenue increased by 30% year-on-year in 2022, but decreased by 15% in 2023 compared to 2022. If the revenue in 2023 was ₹1,10,500 crore, what was the revenue in 2021?
Exam Q 172020Previous Year Pattern
A student's marks increased by 20% from Test 1 to Test 2, and then decreased by 25% from Test 2 to Test 3. The marks in Test 3 were 72. What were the marks in Test 1?
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%