Pie Charts
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Solved Examples
Study MaterialSolved Examples – Pie Charts
Solved examples help students understand the practical application of pie charts, percentages, ratios, central angles, and comparative analysis in Data Interpretation questions. These examples are designed from basic to advanced level and cover important questions frequently asked in SSC, Banking, Railway, Insurance, CAT, CDS, NDA, MBA entrance exams, and various competitive examinations.
Topics Covered in Solved Examples
- Central Angle Calculation
- Percentage Problems
- Ratio Analysis
- Average Problems
- Sector Comparison
- Maximum and Minimum Values
- Combined Pie Chart Interpretation
- Approximation Techniques
Study the Following Pie Chart Data Carefully
The following table represents the monthly expenditure distribution of a family shown through a pie chart concept.
| Category | Percentage | Central Angle |
|---|---|---|
| Food | 25% | 90° |
| Education | 20% | 72° |
| Transport | 15% | 54° |
| Entertainment | 10% | 36° |
| Savings | 30% | 108° |
Assume total monthly expenditure = ₹60000.
Example 1: Central Angle Calculation
Question: Find the central angle representing Food expenditure.
Solution:
Food Percentage = 25%
Central Angle
= (25 / 100) × 360°
= 90°
Answer: 90°
Example 2: Expenditure Calculation
Question: Find the amount spent on Education.
Solution:
Education Percentage = 20%
Total Expenditure = ₹60000
Education Expenditure
= 20% of 60000
= (20/100) × 60000
= ₹12000
Answer: ₹12000
Example 3: Highest Expenditure Identification
Question: Which category has the highest expenditure?
Solution:
Compare percentages:
- Food = 25%
- Education = 20%
- Transport = 15%
- Entertainment = 10%
- Savings = 30%
Highest percentage = 30%
Answer: Savings
Example 4: Difference Calculation
Question: Find the difference between Food and Transport expenditure.
Solution:
Food Expenditure
= 25% of 60000
= ₹15000
Transport Expenditure
= 15% of 60000
= ₹9000
Difference
= 15000 − 9000
= ₹6000
Answer: ₹6000
Example 5: Ratio Problem
Question: Find the ratio of Food expenditure to Entertainment expenditure.
Solution:
Food = 25%
Entertainment = 10%
Required Ratio
= 25 : 10
= 5 : 2
Answer: 5 : 2
Example 6: Percentage Share Problem
Question: What percentage of expenditure is spent on Food and Education together?
Solution:
Food = 25%
Education = 20%
Combined Percentage
= 25 + 20
= 45%
Answer: 45%
Example 7: Combined Expenditure Problem
Question: Find the combined expenditure on Transport and Entertainment.
Solution:
Transport = 15% of 60000
= ₹9000
Entertainment = 10% of 60000
= ₹6000
Combined Expenditure
= 9000 + 6000
= ₹15000
Answer: ₹15000
Example 8: Approximate Percentage Problem
Question: Approximately what fraction of total expenditure is spent on Savings?
Solution:
Savings Percentage = 30%
30% ≈ 1/3
Answer: Approximately 1/3
Example 9: Lowest Expenditure Problem
Question: Which category has the lowest expenditure?
Solution:
Compare percentages:
- Food = 25%
- Education = 20%
- Transport = 15%
- Entertainment = 10%
- Savings = 30%
Lowest percentage = 10%
Answer: Entertainment
Example 10: Central Angle Difference Problem
Question: Find the difference between central angles of Savings and Education.
Solution:
Savings Angle = 108°
Education Angle = 72°
Difference
= 108° − 72°
= 36°
Answer: 36°
Example 11: Percentage to Amount Conversion
Question: Find the amount corresponding to 15% expenditure.
Solution:
15% of 60000
= (15/100) × 60000
= ₹9000
Answer: ₹9000
Example 12: Sector Comparison Problem
Question: How many times is the Savings sector larger than the Entertainment sector?
Solution:
Savings = 30%
Entertainment = 10%
Required Value
= 30 / 10
= 3
Answer: 3 times
Example 13: Total of Multiple Categories
Question: Find the total expenditure on Food, Education, and Transport.
Solution:
Food = ₹15000
Education = ₹12000
Transport = ₹9000
Total
= 15000 + 12000 + 9000
= ₹36000
Answer: ₹36000
Example 14: Fast Approximation Question
Question: Approximately find:
(Food expenditure) ÷ (Education expenditure)
Solution:
Food = ₹15000
Education = ₹12000
Required Value
= 15000 / 12000
≈ 1.25
Answer: Approximately 1.25
Example 15: Total Verification Problem
Question: Verify that total percentage of all sectors equals 100%.
Solution:
25 + 20 + 15 + 10 + 30
= 100%
Answer: Verified
Important Exam Tips
- Always check total value carefully.
- Memorize important angle-percentage conversions.
- Use approximation techniques smartly.
- Compare sectors visually before calculations.
- Avoid unnecessary lengthy calculations.
- Improve speed in percentage calculations.
- Practice previous year Data Interpretation questions.
Common Mistakes to Avoid
- Ignoring total value.
- Wrong angle calculations.
- Incorrect percentage conversions.
- Ignoring units mentioned.
- Assuming unavailable data.
Practicing solved examples regularly improves analytical thinking, calculation speed, and accuracy in solving Pie Chart Data Interpretation questions in competitive examinations.