Practice Questions
Concept Explanation
Mixed percentage problems combine two or more ideas: successive change, comparison, population, marks, income, or error — typical of final-round placement aptitude sections.
Strategy
- Translate words into multipliers (e.g. "20% more" → ×1.2).
- Identify the correct base for each percentage.
- Draw a quick table for multi-step problems.
Alligation Link
When mixing two solutions with different concentrations, weighted averages connect to percentage concepts.
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Q1 Medium
A number is increased by 20%, then the result is decreased by 25%. Net change is:
Explanation1.2 × 0.75 = 0.9 → 10% decrease. -
Q2 Medium
If 30% of A is 40% of B, then A:B is:
Explanation0.3A = 0.4B → A/B = 4/3. -
Q3 Hard
Population 50,000 increases 10% annually for 2 years. Final population is:
Explanation50,000 × 1.1² = 60,500. -
Q4 Medium
A shop marks goods 40% above CP and gives 20% discount. Profit percent is:
ExplanationSP = 1.4 × 0.8 = 1.12 × CP → 12% profit. -
Q5 Hard
In an exam, A scores 20% more than B and B scores 25% less than C. If C scored 400, A scored:
ExplanationB = 0.75 × 400 = 300. A = 1.2 × 300 = 360. -
Q6 Medium
Price up 20%, consumption down 15%. Expenditure changes by:
Explanation1.2 × 0.85 = 1.02 → 2% increase. -
Q7 Hard
Income Rs. 24,000, saves 25%. After income rises 20% with same expenditure, savings percent of new income is:
ExplanationExpenditure = 18,000. New income = 28,800. New savings = 10,800. Percent = 10,800/28,800 = 37.5%.
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Q8 Easy
A is 20% of B and B is 25% of C. A is what percent of C?
ExplanationA = 0.2 × 0.25C = 0.05C → 5%. -
Q9 Medium
Successive discounts of 10% and 20% equal a single discount of:
ExplanationRemaining = 0.9 × 0.8 = 0.72 → 28% discount. -
Q10 Hard
An article's price is increased by 10%, then decreased by 10%, then increased by 5%. Net change is:
ExplanationNet multiplier = 1.1 × 0.9 × 1.05 = 1.0395 → 3.95% increase. -
Q11 Hard
If 20% of (A + B) = 50% of (A − B), then A:B is:
Explanation0.2(A+B) = 0.5(A−B) → 2A+2B = 5A−5B → 7B = 3A → A:B = 7:3. -
Q12 Hard
A student needs 40% to pass. He gets 35% and fails by 40 marks. Maximum marks are:
Explanation5% of max = 40 → max = 800. -
Q13 Medium
Town population 80,000: +15% then −10%. Final population is:
Explanation80,000 × 1.15 × 0.9 = 82,800. -
Q14 Easy
True weight 2 kg measured as 2.1 kg. Percentage error is:
ExplanationError = 0.1 on 2 → 5%.
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DS1 Medium
What is the net percentage change?
Statement IA value increases 20% then decreases 25%.
Statement IIThe starting value is 400.
ExplanationNet multiplier 0.9 → 10% decrease. Final = 360. Both change sequence and starting value are needed. -
DS2 Easy
What is A as a percent of C?
Statement IA is 20% of B.
Statement IIB is 25% of C.
ExplanationA = 0.05C → 5%. Both needed.
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DS3 Medium
What is the selling price?
Statement IMarked price is 40% above cost price of Rs. 500.
Statement IIA discount of 20% on marked price is given.
ExplanationMP = 700. SP = 700 × 0.8 = Rs. 560. -
DS4 Hard
What is the final population?
Statement IInitial population is 50,000.
Statement IIIt grows 10% per year for 2 years.
Explanation50,000 × 1.1² = 60,500.