Quick Concept Summary
Mixed-chart questions present data in two forms at once — for example, a table of yearly totals plus a pie chart of category shares. To answer, you transfer a value (usually the total) from one chart into the other. The maths is basic percentage/ratio work; the real skill is linking the charts correctly.
Core Conversions
| You have | You want | Formula |
|---|---|---|
| Total + percentage | Part value | Part = Total × % ÷ 100 |
| Total + pie angle | Sector value | Value = Total × angle ÷ 360 |
| Part + total | Percentage | (Part ÷ Total) × 100 |
| Two parts | Ratio | Part₁ : Part₂ |
The Method
1. Identify what each chart provides (one usually gives totals, the other shares). 2. Find the total that the question's category refers to. 3. Apply the percentage or angle to that total. 4. Compare or combine values as the question asks.
<em>Tip: jot the absolute value of each sector once — many questions reuse it.</em>
Worked Examples
Example 1: A table shows Company X sold 4,000 units in 2024. A pie chart shows Product A = 25% of sales. Units of Product A? 4,000 × 25 ÷ 100 = 1,000 units.
Example 2: Pie chart: Marketing = 72°. Table: total budget = ₹50 lakh. Marketing spend? 50 × 72 ÷ 360 = ₹10 lakh.
Example 3: In 2023, total = 8,000; Product B = 30%. In 2024, total = 10,000; Product B = 24%. Change in Product B units? 2023: 2,400; 2024: 2,400 → no change (a classic "percentage fell but total rose" trap).
Example 4: Product A = 1,000 units out of a 4,000 total. What percentage is Product A? (1,000 ÷ 4,000) × 100 = 25%.
Common Mistakes
- Applying a percentage to the wrong total (different year/category).
- Confusing pie degrees with percentages (360° = 100%).
- Forgetting that a falling percentage can still mean a rising absolute value if the total grew.
Exam Tips
- Always pin down the total first — it is the bridge between the two charts.
- Convert key pie sectors to absolute numbers once and reuse them.
- Watch the units (lakh, thousand, %) — mismatched units cause silly errors.