Practice Questions
Concept Explanation
Percentage DS items test whether you can find a unique percent, part, or whole—watch the base of every percentage.
Standard Answer Choices
- A — Statement I alone is sufficient; Statement II alone is not.
- B — Statement II alone is sufficient; Statement I alone is not.
- C — Both together are sufficient, neither alone.
- D — Either statement alone is sufficient.
- E — Neither alone nor together is sufficient.
Percentage DS Focus
Identify whether the question asks for x% of N, what percent one value is of another, or increase/decrease on an original base.
Common Traps in Percentage Problems
- Applying successive changes on the wrong base.
- Assuming part and whole when only one is given.
- Mixing percentage points with percentage change.
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Q1 Easy
What is 20% of 450?
Explanation20% of 450 = 0.20 × 450 = 90. -
Q2 Easy
If 25% of a number is 75, the number is:
ExplanationN = 75 × 4 = 300. -
Q3 Easy
What percent is 45 of 180?
Explanation(45/180) × 100 = 25%. -
Q4 Easy
A salary of Rs. 20,000 increases by 10%. New salary is:
ExplanationIncrease = 2,000; new salary = Rs. 22,000. -
Q5 Medium
Population rises from 80,000 to 92,000. Percentage increase is:
ExplanationIncrease = 12,000; (12,000/80,000) × 100 = 15%. -
Q6 Medium
Price drops from Rs. 500 to Rs. 400. Percentage decrease is:
Explanation(100/500) × 100 = 20%. -
Q7 Medium
For “What is N?” — I: 20% of N is 84; II: N exceeds 400 by 20. DS answer?
ExplanationI: N = 420. II: N = 420. Each alone is sufficient.
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Q8 Medium
For “What percent is x of y?” — I: x = 45; II: y = 180. DS answer?
ExplanationNeed both part and whole: (45/180) × 100 = 25%. -
Q9 Hard
Successive 10% increase then 10% decrease on Rs. 100 gives final value:
ExplanationAfter +10%: 110; after −10% on 110: 99. -
Q10 Medium
120% of 350 equals:
Explanation1.2 × 350 = 420. -
Q11 Easy
If income is Rs. 50,000 and 30% is saved, savings are:
Explanation30% of 50,000 = 15,000. -
Q12 Easy
Marks scored: 108 out of 360. Percentage score is:
Explanation(108/360) × 100 = 30%. -
Q13 Hard
33⅓% of a number is 108. The number is:
Explanation33⅓% = 1/3; N = 108 × 3 = 324. -
Q14 Hard
For “Is the percentage greater than 50%?” — I: decimal form is 0.55; II: fraction form is 11/20. DS answer?
ExplanationEach statement alone gives 55%, so the answer is yes.
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DS1 Easy
What is the value of N?
Statement IN is 30% of 400.
Statement IIN is 20 more than 100.
ExplanationStatement I: N = 120. Statement II: N = 120. Each alone is sufficient. -
DS2 Medium
What percent is x of y?
Statement Ix = 45.
Statement IIy = 180.
ExplanationNeed both values: (45/180) × 100 = 25%.
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DS3 Medium
What is the original price before a discount to Rs. 400?
Statement IThe discount amount is Rs. 100.
Statement IIThe discounted price is 80% of the original.
ExplanationStatement I: Original = 400 + 100 = 500. Statement II: 0.80 × Original = 400 ⇒ Original = 500. -
DS4 Easy
By what percent did population grow from Year 1 to Year 2?
Statement IYear 1 population was 80,000.
Statement IIYear 2 population was 92,000.
ExplanationNeed both years: increase = 12,000; percent = 15%.