Data Interpretation for Banking Mocks | Banking Quant Mastery

Why This Chapter Matters

DI is where arithmetic accuracy and time pressure collide. The job is not just to compute; it is to decide what must be computed and what can be approximated.

Core Ideas

Read the unit, the base total, and the year labels before solving.
If options are wide apart, approximation is usually enough.
Tables often become faster than graphs because every value is explicit.
Mixed graphs can usually be decomposed into one percentage step and one ratio step.
Production-ready DI content can convert chart images into text tables without losing the actual logic of the set.
When percentages are based on a total pool, first convert the pool into absolute values before comparing categories.
In multi-year tables, identify whether the question needs absolute change, percentage change, ratio, or average before touching the numbers.

High-Value Formulas

Concept	Formula / Rule
Percentage from part and total	$\frac{part}{total} \times 100$
Average from grouped values	$\frac{sum of values}{n}$
Export-import ratio	$ratio = \frac{exports}{imports}$
Net difference	$deposits - withdrawals$
Weighted category value	$total \times \frac{category %}{100}$

How To Approach Questions

Mark the exact dataset the question needs.
Avoid computing unrelated rows or columns.
When totals are given in percentages, convert them one layer at a time.
If a graph is missing, restate the usable values in text form before solving.
If multiple questions use the same set, compute one or two reusable intermediate values once and reuse them.

Worked Examples

Example 1

Prompt: Use a table-based set when the image is not available. Rebuild only the data you need in text form.

Approach: This is the safest production approach for mobile-friendly DI content because it preserves the logic without copying source graphics.

Example 2

Prompt: A ratio chart says company A had export-import ratio $175 : 100$ in a year and imports were later increased by $40%$ . What is the new export-import ratio if exports stay fixed?

Approach: Treat exports as $175 x$ and imports as $100 x$ . The increased imports become $140 x$ , so the new ratio is $\frac{175}{140} = 1.25$ .

Example 3

Prompt: A budget pie is converted into text: salaries $35%$ , rent $25%$ , marketing $20%$ of a total spend of $24$ lakhs. Find the salary spend.

Approach: Salary spend $= 35%$ of $24 = 8.4$ lakhs.

Example 4

Prompt: A branch table shows deposits $72$ lakh and withdrawals $54$ lakh. Find the net inflow.

Approach: Net inflow $= 72 - 54 = 18$ lakh.

Common Mistakes

Missing the unit scale such as hundreds, thousands, or crores.
Doing exact arithmetic when option gaps allow approximation.
Reading the wrong row because the chart labels were skimmed.
Mixing enrolled counts with passed counts from different parts of the same set.
Using a category percentage directly without checking whether it is of the total, of a subgroup, or of the previous year.

Quick Revision

Good DI performance is a mix of selective reading, fast percentage logic, and disciplined approximation.

15. Data Interpretation for Banking Mocks