Core ConceptRead this first — the foundation of the topic
Pie charts are circular diagrams that show how a whole is divided into parts. Think of a pizza cut into slices - each slice represents a portion of the total. In SSC CGL, pie charts appear in 80% of papers, usually with 2-3 questions worth 6-9 marks.
Key RulesCore rules you must know cold
The complete circle equals 360 degrees. Each part is shown as a sector (slice). The angle of each sector is proportional to the data it represents. All sectors together must equal 360 degrees or 100%.
Formula BlockMemorise — at least one formula appears in every paper
Block:
• Central Angle = (Value/Total Value) × 360°
• Percentage = (Value/Total Value) × 100
• Value = (Central Angle/360°) × Total Value
• Ratio Formula: If angle is θ°, then ratio = θ/360
Exam PatternsWhat examiners ask — read before attempting PYQs
SSC asks three main question types. First, direct calculations from given percentages or angles. Second, comparison questions asking 'how much more' or 'what is the ratio'. Third, application problems combining pie charts with other topics like profit-loss or averages.
Powerful Shortcut #1 - The 36° Rule: Since 360° = 100%, then 36° = 10%.
This means 18° = 5%, 72° = 20%, 108° = 30%. Memorize these common angle-percentage pairs to solve questions in 10 seconds.
Shortcut #2 - Direct Proportion Method: Instead of calculating percentages, use direct ratios. If sector A has 60° and sector B has 120°, then B is exactly double A. No complex calculations needed.
Worked ExampleSolve this step-by-step before moving on
1
Step 1
Marketing angle = 72°
2
Step 2
Using formula: Value = (72°/360°) × 50,000
3
Step 3
= (1/5) × 50,000 = ₹10,000
Alternate Quick Method: 72° = 20% (using 36° rule), so 20% of 50,000 = ₹10,000
Worked Example 2: In a pie chart showing student preferences, Cricket gets 126°, Football gets 90°, Hockey gets 54°. What percentage more students prefer Cricket over Hockey?
1
Step 1
Cricket = 126°, Hockey = 54°
2
Step 2
Difference = 126° - 54° = 72°
3
Step 3
72° = 20% (using shortcut)
4
Step 4
Hockey percentage = 54°/360° = 15%
5
Step 5
Cricket percentage = 126°/360° = 35%
6
Step 6
Cricket is 35% - 15% = 20% more than Hockey
Shortcut #3 - The Remainder Trick: When some sectors are given and you need to find the remaining sector, don't calculate each percentage. Simply subtract given angles from 360°. If three sectors are 80°, 120°, and 70°, the fourth sector is 360° - 270° = 90°.
Most Common Trap - The Percentage vs Angle Confusion: Students often mix up
When to UseQuickly decide which method to apply in the exam
percentages and when to use angles. Remember: if the question gives percentages, convert to angles by multiplying by 3.6.
If it gives angles, convert to percentages by dividing by 3.6. This single mistake costs students 2-3 marks per paper.
Another Critical Error: Students forget that pie charts represent parts of a whole.
You cannot add values from two different pie charts directly unless they have the same total value. Always check if the total values are same before making comparisons.
Pro Tip for Complex Questions: When pie charts combine with other topics, first extract the basic values from the pie chart, then apply the second concept.
What is the ratio of Clothing sales to Books & Stationery sales?
Practice 2easy
What percentage of total sales is contributed by Sports & Outdoors and Books & Media combined?
Practice 3easy
What is the sales value (in lakhs) of the Electronics category?
Practice 4easy
What is the combined sales value (in lakhs) of Clothing and Home & Kitchen categories?
Practice 5easy
If the company aims to increase total sales to ₹6,000 lakhs next year while maintaining the same percentage distribution, what will be the sales value of Home & Kitchen category (in lakhs)?
Practice 6easy
What is the sales value (in lakhs) of the Electronics category?
Practice 7easy
What is the combined sales value (in lakhs) of Clothing and Home & Kitchen categories?
Practice 8easy
By what amount (in lakhs) do Electronics sales exceed Sports & Outdoors sales?
Practice 9easy
What is the ratio of sales of Books & Media to Clothing?
Practice 10medium
If Home & Garden sales increase by 25% next year while total sales remain ₹5,000 lakhs, what will be the new percentage share of Home & Garden?
Practice 11medium
What is the ratio of Sports & Outdoors sales to Books & Media sales?
Practice 12medium
By how many lakhs do the combined sales of Electronics and Home & Garden exceed the combined sales of Sports & Outdoors and Books & Media?
Practice 13medium
By what amount does the revenue from Clothing exceed that from Books & Media?
Practice 14medium
What is the revenue generated from the Electronics category?
Practice 15medium
Combined sales of Clothing and Books & Media together constitute what percentage of total sales?
Practice 16medium
If the company's revenue increases by 20% next year and the percentage distribution remains the same, what will be the revenue from Clothing category next year?
Practice 17medium
What is the difference in sales (in lakhs) between Electronics and Clothing categories?
Practice 18medium
What is the combined revenue from Sports & Outdoors and Home & Garden categories?
Practice 19hard
What is the ratio of production of Electronics division to Packaging division in 2023?
Practice 20hard
What is the average production (in thousand units) of Automotive, Textiles, and Machinery divisions combined in 2023?
6 more practice questions in the Study Panel
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