Introduction
Percentages are one of the most important topics in Quantitative Aptitude and are frequently asked in IBPS PO, SBI PO, RBI Assistant, LIC AAO, SSC CGL, RRB, Insurance, and other competitive exams. A strong understanding of percentages also helps in topics like Profit and Loss, Simple Interest, Compound Interest, Data Interpretation, Partnership, and Ratio & Proportion.
In this first part of the BrainQuro Percentage Series, you’ll practice 10 original percentage questions designed according to the latest banking exam pattern. Instead of lengthy calculations, every question includes a shortcut solution, highlights common mistakes, and shares banking exam tips to improve your speed and accuracy.
Whether you’re preparing for bank exams or government competitive exams, these questions will strengthen your concepts and help you solve percentage problems more efficiently.
Table of Contents
Question 1
Question
After a 20% increase, the price of a study table became ₹7,200. What was its original price?
Given
- Final Price = ₹7,200
- Increase = 20%
Formula
Original Price = Final Price × 100 / (100 + Increase%)
⚡ Shortcut Solution
After a 20% increase, the new price becomes 120% of the original price.
120% = 6 parts
₹7,200 = 6 parts
1 part = ₹7,200 ÷ 6 = ₹1,200
Original Price = 5 parts
= ₹1,200 × 5
= ₹6,000
✅ Final Answer
₹6,000
⚠️ Common Mistake
Many students calculate 20% of ₹7,200 and subtract it. This is incorrect because ₹7,200 is already the increased price, not the original price.
💡 Banking Exam Tip
Whenever you see “after an increase/decrease”, first identify what percentage the final value represents (e.g., 120%, 80%, 75%) and solve using parts instead of formulas.
Question 2
Question
A shopkeeper offered a 25% discount on a microwave oven. If the customer paid ₹27,000, find the marked price of the microwave oven.
Given
- Discount = 25%
- Selling Price = ₹27,000
Formula
Marked Price = Selling Price × 100 / (100 − Discount%)
⚡ Shortcut Solution
After a 25% discount, the customer pays 75% of the marked price.
75% = 3 parts
₹27,000 = 3 parts
1 part = ₹9,000
Marked Price = 4 parts
= ₹9,000 × 4
= ₹36,000
✅ Final Answer
₹36,000
⚠️ Common Mistake
Many candidates simply add 25% to ₹27,000. This is incorrect because ₹27,000 represents 75%, not 100%.
💡 Banking Exam Tip
For reverse percentage questions, remember these common values:
- After 20% decrease → Remaining = 80%
- After 25% decrease → Remaining = 75%
- After 40% decrease → Remaining = 60%
These save a lot of time in prelims.
Question 3
Question
A person spends 65% of his monthly income. If his monthly savings are ₹21,000, what is his monthly income?
Given
- Expenditure = 65%
- Savings = ₹21,000
Formula
Income = Savings × 100 / Savings%
⚡ Shortcut Solution
If expenditure is 65%, then savings are 35%.
35% = 7 parts
₹21,000 = 7 parts
1 part = ₹3,000
100% = 20 parts
Income = ₹3,000 × 20
= ₹60,000
✅ Final Answer
₹60,000
⚠️ Common Mistake
Students often assume ₹21,000 is 65% of the income. Always check whether the given amount is income, expenditure, or savings.
💡 Banking Exam Tip
Whenever the remaining percentage is 35%, 40%, 60%, 75%, convert it into simple ratio form (7:20, 2:5, 3:5, 3:4). This makes reverse percentage questions much faster.
Ye format concise hai, website-friendly hai, aur students ko real exam shortcuts sikhata hai. Agle questions me difficulty aur thodi badhayenge aur har question ka pattern alag rakhenge.
Question 4
Question
The population of a town increased by 25% in the first year and then decreased by 20% in the second year. If the present population is 60,000, what was the population of the town two years ago?
Given
- First Year Increase = 25%
- Second Year Decrease = 20%
- Present Population = 60,000
Formula
Original Population = Present Population × 100 × 100 ÷ (125 × 80)
⚡ Shortcut Solution
Increase of 25% means:
100 → 125
Decrease of 20% means:
125 → 100
This means after both changes, the population comes back to the original value.
So,
Original Population = Present Population = 60,000
✅ Final Answer
60,000
⚠️ Common Mistake
Many students think +25% and −20% cancel each other by chance. They don’t. They cancel here because:
- 125%×80%=100%
This is a special case, not a general rule.
💡 Banking Exam Tip
Remember these important successive percentage changes:
- +25% followed by −20% = No overall change
- +20% followed by −20% = 4% decrease
- +10% followed by −10% = 1% decrease
Questions based on successive percentage changes are frequently asked in IBPS PO, SBI PO, and SSC CGL.
Question 5
Question
The price of a washing machine was increased by 25%. Due to poor sales, the increased price was then reduced by 20%. If the final selling price is ₹30,000, find the original price of the washing machine.
Given
- Increase = 25%
- Decrease = 20%
- Final Price = ₹30,000
Formula
Original Price = Final Price × 100 × 100 ÷ (125 × 80)
⚡ Shortcut Solution
A 25% increase changes the price from 100 to 125.
A 20% decrease changes it from 125 back to 100.
So, there is no overall change.
Therefore,
Original Price = ₹30,000
✅ Final Answer
₹30,000
⚠️ Common Mistake
Many students calculate 25% − 20% = 5% increase, which is incorrect. Successive percentage changes are not added or subtracted directly.
💡 Banking Exam Tip
Remember this special shortcut:
+25% followed by −20% = No overall change
It can save 20–30 seconds in the exam.
Question 6
Question
A student needs 40% marks to pass an examination. He scored 228 marks and failed by 12 marks. Find the maximum marks of the examination.
Given
- Passing Marks = 40%
- Marks Obtained = 228
- Failed By = 12 Marks
Formula
Maximum Marks = Passing Marks × 100 ÷ Passing Percentage
⚡ Shortcut Solution
Passing Marks
= 228 + 12
= 240
Now,
40% = 2/5
If 2 parts = 240
Then,
1 part = 120
Total (5 parts)
= 120 × 5
= 600
✅ Final Answer
600 Marks
⚠️ Common Mistake
Many students directly take 228 as 40%, forgetting that the student failed by 12 marks.
💡 Banking Exam Tip
In pass/fail questions:
- Failed by x → Add x
- Passed by x → Subtract x
before calculating the percentage.
Question 7
Question
A trader sold a mixer grinder after allowing a 10% discount on the marked price. If the customer paid ₹5,850, find the marked price.
Given
- Discount = 10%
- Selling Price = ₹5,850
Formula
Marked Price = Selling Price × 100 ÷ (100 − Discount%)
⚡ Shortcut Solution
After a 10% discount, the customer pays 90% of the marked price.
90% = 9 parts
₹5,850 = 9 parts
1 part = ₹650
Marked Price = 10 parts
= ₹650 × 10
= ₹6,500
✅ Final Answer
₹6,500
⚠️ Common Mistake
Many candidates add 10% directly to ₹5,850. The given amount represents 90%, not 100%.
💡 Banking Exam Tip
Whenever you see 10%, 20%, 25%, or 50%, convert them into simple ratios like 9:10, 4:5, 3:4, or 1:2 to solve mentally.
Question 8
Question
The salary of an employee was increased by 20%. If his new monthly salary is ₹54,000, find his original monthly salary.
Given
- Increase = 20%
- New Salary = ₹54,000
Formula
Original Salary = New Salary × 100 ÷ (100 + Increase%)
⚡ Shortcut Solution
After a 20% increase, the new salary becomes 120% of the original salary.
120% = 6 parts
₹54,000 = 6 parts
1 part = ₹9,000
Original Salary = 5 parts
= ₹9,000 × 5
= ₹45,000
✅ Final Answer
₹45,000
⚠️ Common Mistake
Many students calculate 20% of ₹54,000 and subtract it. Remember, ₹54,000 is 120%, not 100%.
💡 Banking Exam Tip
For reverse percentage questions, think in parts (100%, 120%, 80%, 75%) instead of using lengthy formulas.
Question 9
Question
In an examination, 35% of the students failed. If 845 students passed, find the total number of students who appeared for the examination.
Given
- Failed = 35%
- Passed = 845 Students
Formula
Total Students = Passed × 100 ÷ Passed%
⚡ Shortcut Solution
If 35% failed, then 65% passed.
65% = 13/20
845 = 13 parts
1 part = 845 ÷ 13 = 65
Total = 20 parts
= 65 × 20
= 1,300
✅ Final Answer
1,300 Students
⚠️ Common Mistake
Many candidates directly treat 845 as 35% instead of realizing it represents the passed students (65%).
💡 Banking Exam Tip
Whenever pass/fail percentages are given, first calculate the remaining percentage before solving.
Question 10
Question
A shopkeeper first increased the marked price of an item by 40% and then offered a 30% discount on the increased price. If the customer finally paid ₹4,900, what was the original marked price before the increase?
Given
- Increase = 40%
- Discount = 30%
- Final Selling Price = ₹4,900
Formula
Original Price = Final Price × 100 × 100 ÷ (140 × 70)
⚡ Shortcut Solution
Assume the original marked price = 100 parts.
After a 40% increase:
100 → 140 parts
After a 30% discount:
140 × 70% = 98 parts
So, 98 parts = ₹4,900
1 part = ₹4,900 ÷ 98 = ₹50
100 parts = ₹5,000
✅ Final Answer
₹5,000
⚠️ Common Mistake
Many students assume +40% and −30% = +10%, which is incorrect. Successive percentage changes must be applied one after the other.
💡 Banking Exam Tip
Remember this shortcut:
Net Percentage Change = a+b+ab100a + b + \frac{ab}{100}a+b+100ab
- Use + for increase.
- Use − for decrease.
This shortcut is extremely useful for successive percentage questions in IBPS PO, SBI PO, SSC CGL, and RBI Assistant.
Readers preparing for Quantitative Aptitude should also explore:
Shortcut Trick of the Day
⭐ Shortcut Trick
Memorize these fraction-to-percentage conversions. They appear repeatedly in banking exams.
| Fraction | Percentage |
|---|---|
| 1/2 | 50% |
| 1/3 | 33⅓% |
| 1/4 | 25% |
| 1/5 | 20% |
| 1/8 | 12.5% |
| 3/8 | 37.5% |
| 2/5 | 40% |
| 3/5 | 60% |
| 4/5 | 80% |
| 7/20 | 35% |
Learning these values can save 10–20 seconds on many arithmetic questions.
Frequently Asked Questions (FAQ)
1. Are these Percentage questions suitable for IBPS PO and SBI PO?
Yes. These questions are designed according to the latest banking exam pattern and are suitable for IBPS PO, SBI PO, RBI Assistant, LIC AAO, RRB, SSC CGL, and other competitive exams.
2. Are the questions original?
Yes. Every question in the BrainQuro Percentage Series is created from scratch with unique values and verified calculations.
3. Why do these questions use shortcut solutions instead of lengthy methods?
Competitive exams focus on speed and accuracy. Shortcut solutions help candidates solve questions faster while maintaining accuracy.
4. Is this series suitable for beginners?
Yes. The difficulty increases gradually from basic concepts to banking exam level, making it suitable for both beginners and advanced learners.
