# GRE Data Interpretation: Tables, Graphs and Tips | topin

GRE guidesData Interpretation

Section

Quantitative Reasoning, usually a single set of a few questions

Displays

Tables, bar charts, line graphs, pie charts, sometimes two displays together

Formats

Any Quant format: select one, select one or more, Numeric Entry

Common tasks

Percent change, percent of a total, ratios, averages and reading values

Accuracy

Displays are drawn to be read accurately; "approximately" signals that estimation is fine

## How it works

Several consecutive questions refer to the same display, which stays on screen for each question in the set. The questions test reading values correctly and then doing standard arithmetic with them, most often percentages, ratios and averages. The maths is rarely hard; most lost points come from reading the wrong row, series or unit.

## Worked example

Books sold by a shop, by quarter (units): Q1 fiction 150, non-fiction 90; Q2 fiction 180, non-fiction 120; Q3 fiction 100, non-fiction 80; Q4 fiction 160, non-fiction 120\. By approximately what percent did the shop's total book sales increase from Q3 to Q4?

1. A36%
2. B50%
3. C56%
4. D60%
5. E100%
Show the answer

56%

Total sales were 100 + 80 = 180 in Q3 and 160 + 120 = 280 in Q4, an increase of 100\. Percent change is the increase divided by the starting value: 100 ÷ 180 ≈ 0.556, or about 56%. The traps: 36% divides by the Q4 total (100 ÷ 280), 60% is the fiction change alone (60 ÷ 100), 50% is the non-fiction change alone (40 ÷ 80) and 100% is the raw increase read as a percent.

## A method for Data Interpretation

1. 1  
### Read the whole display first  
Before question one, read the title, axis labels, units, legend and any notes. Check whether values are counts or percentages and whether they are in units, thousands or millions.
2. 2  
### Find exactly what the question asks for  
Identify the category, time period and measure the question names, such as "total" versus one series. Many wrong answers come from answering a nearby question.
3. 3  
### Pull only the values you need  
Write down the few numbers the question requires, with their labels, rather than working from the screen in your head.
4. 4  
### Use the right formula  
Percent change is (new - old) ÷ old. Percent of a total is part ÷ whole. Know which base each question needs before you divide.
5. 5  
### Estimate when the choices allow  
If the question says approximately or the choices are spread out, round the values and compare. Use the calculator only when choices are close together.

## Traps to avoid

* Dividing by the new value instead of the original when calculating percent change.
* Reading one series or category when the question asks for a total, or the reverse.
* Missing a unit note such as "in thousands" and answering a thousand times too small.
* Treating a percentage from a pie chart as a count without multiplying by the total.
* Assuming a trend continues beyond the data shown.

## Data Interpretation FAQs

How many Data Interpretation questions are on the GRE?

On the shorter GRE there is usually one set of a few questions sharing a display. The exact number varies from test to test.

Can I use the calculator on Data Interpretation questions?

Yes, the on-screen calculator is available throughout Quant. It helps with awkward division, but estimating is often faster when the choices are spread out.

What maths do Data Interpretation questions need?

Mostly percentages, percent change, ratios, averages and reading values from graphs. The challenge is reading the display accurately rather than advanced maths.

How can I practise GRE Data Interpretation?

Work through sets that combine tables and charts, and after each one note whether your mistakes came from reading the display or from the arithmetic. topin's free GRE mock includes a full data set under real timing.

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