Efficient reasoning and execution across Data Insights formats
Use a repeatable workflow to finish the complete DI question accurately and efficiently.
GMAT35 min study guide8 indexed sections
BY THE END, YOU CAN
Explain choose calculation only when necessary
Explain calculator in DI only
Explain estimate before calculating
Explain track units and rounding
Explain separate question from response parts
Explain manage shared-source reading
Explain verify all requested components
Explain time and review decisions
BEFORE YOU START
Basic skills from the five DI formats
Comfort with ratios, units and logical comparisons
Original educational lesson. Work through the examples before revealing the practice answers. This original lesson supports current GMAT study through an editorial skill map. It does not reproduce official questions, predict exam content or guarantee a score.
LEARN THROUGH ORIGINAL PRACTICE
Original GMAT-style worked examples and practice
All passages, examples and exercises here are original. No official GMAC questions, choices or explanations are reproduced. This independent preparation resource is not affiliated with or endorsed by GMAC. GMAT is a trademark of the Graduate Management Admission Council.
01 / UNDERSTAND & APPLY
Recognize the task before choosing a method
Current GMAT Data Insights includes Data Sufficiency, Multi-Source Reasoning, Table Analysis, Graphics Interpretation and Two-Part Analysis. The same arithmetic can appear in several formats, but the response task changes: classify information, evaluate evidence, judge rows, complete blanks or select a pair.
Make a short target note: what must be known or selected, what units apply, and how many response parts are requested. A three-row binary prompt is one question with three judgments; a two-blank graphic is one question with two selections.
ORIGINAL WORKED EXAMPLE
Sufficiency needs logic before calculation
Data Sufficiency: Is positive integer n divisible by 3? (1) n is divisible by 6. (2) n is divisible by 9. Select one case: A only 1 sufficient; B only 2; C only together; D each alone; E not even together.
Every multiple of 6 is divisible by 3, so statement 1 independently gives yes.
Every multiple of 9 is divisible by 3, so statement 2 independently gives yes.
No value of n needs to be calculated, and no combining is needed.
Answer D
02 / UNDERSTAND & APPLY
Choose calculation only when it changes the decision
Before computing, ask whether order, sign, bounds, cancellation or a direct source statement settles the question. If all candidate answers differ widely, a good estimate may suffice. If an inequality sits near a cutoff, exact calculation may be necessary.
An on-screen calculator is available in DI; the standard Quantitative Reasoning section does not provide it. Use the tool for arithmetic after building the right expression. A calculator cannot choose a denominator or repair a mismatched unit.
ORIGINAL WORKED EXAMPLE
Eliminate by a hard constraint first
Multi-Source set: Quote tab — A costs $9/unit plus $15 shipping and delivers in 2 days; B costs $10/unit plus $5 shipping and delivers in 3 days. Policy tab — order exactly 10 units, total ≤$110, delivery ≤2 days. Select the feasible supplier, A or B.
B fails the deadline immediately, independent of its price.
For A, total=10×9+15=$105≤$110 and delivery meets 2 days.
One supplier satisfies every condition; there is no reason to perform unrelated comparisons.
Answer A
ORIGINAL PRACTICE · 1
Without full long division, is 497/503 greater than 1? Select Yes or No.
Reveal answer & reasoning
No
Both numbers are positive and the numerator is smaller than the denominator. Exact decimal calculation cannot change the answer.
03 / UNDERSTAND & APPLY
Estimate first, then calculate to the needed precision
An estimate is a reasonableness check and sometimes a complete solution. For 198×0.31, expect a little above 60, not 6 or 600. Exact result 61.38 then fits that scale.
Near a decision boundary, an estimate may be too coarse. Keep enough precision to distinguish the available choices or prove the requested inequality. Do not round an intermediate number so aggressively that it crosses a threshold.
Full-size scientific diagram. Swipe or scroll horizontally; keyboard users can focus the diagram and use arrow keys.
Original data. The two requested comparisons have different units: packages and percent.
ORIGINAL WORKED EXAMPLE
A two-blank graphic with exact labels
The original delivery chart shows Day 1:48 packages and Day 2:60 packages. Complete both blanks: absolute increase [12/25/48] packages; percentage increase [12/20/25]%.
Estimate: growth from roughly 50 to60 is around20%, so 25% is plausible while12% is too small.
Exact difference=60−48=12 packages.
Relative increase=12/48=1/4=25%; both blanks are now resolved.
Answer 12 packages; 25%
ORIGINAL PRACTICE · 1
A graph labels a rise from 240 to 300. Choose its percentage increase from {20%,25%,60%}.
Reveal answer & reasoning
25%
Increase=60 and initial base=240, so 60/240=25%. Dividing by final 300 gives 20%, a different quantity.
ORIGINAL PRACTICE · 2
A qualifying ratio must be at least 0.667. Does 2/3 qualify when the threshold is exact? Select Yes or No.
Reveal answer & reasoning
No
2/3=0.6666… is below 0.667. Rounding the ratio to three decimals before comparison would change the decision improperly.
04 / UNDERSTAND & APPLY
Carry units and postpone rounding
Write units beside intermediate values so conversion errors become visible. A rate in units/minute multiplied by hours needs a factor of60. A revenue chart in thousands of dollars cannot be read as raw dollars.
When a task requires whole containers, buses or shifts, the final rounding rule follows the situation: required capacity generally rounds up. A reported measurement may instead require nearest-unit rounding. Decide the rule after understanding the target.
ORIGINAL WORKED EXAMPLE
Paired unit-sensitive answers
Two-Part: A pump fills 15 liters/minute for 2 hours. Select Total liters and Number of 500-liter tanks needed to hold all the water from {3,4,30,120,1800}; select one per column. Tanks are initially empty.
1,800/500=3.6 tanks of capacity, so at least 4 whole tanks are needed.
The two columns have different units; 120 is operating minutes, not either requested answer.
Answer Total liters: 1800; Tanks: 4
ORIGINAL PRACTICE · 1
A chart gives revenue 2.4 in millions of dollars and costs 900 in thousands of dollars. What is profit in dollars?
Reveal answer & reasoning
$1,500,000
Convert revenue to $2,400,000 and costs to $900,000, then subtract. Subtracting 2.4−900 mixes scales.
ORIGINAL PRACTICE · 2
A van holds at most 18 boxes. How many vans are required for 73 boxes if every box must be transported in one trip?
Reveal answer & reasoning
5 vans
73/18 is slightly above 4, and 4 vans hold only 72 boxes. Capacity requires rounding up to 5.
05 / UNDERSTAND & APPLY
Map shared sources once, then read with a purpose
For a shared-source set, first locate definitions, tables and rules. For each question, revisit only the needed values and exceptions. Preserve the map across questions, but reset question-specific assumptions and targets.
An information map is not a summary of everything. “Tab 1 prices; tab 2 eligibility; tab 3 updated deadline” may be enough. Check whether an update replaces or supplements an earlier rule rather than treating both as simultaneously binding.
ORIGINAL PRACTICE · 1
A quote tab gives standard delivery 5 days. An update states expedited delivery replaces standard delivery with 2 days at a $40 surcharge. Which delivery time applies when expedited is chosen, and is the surcharge ignored? Give two answers.
Reveal answer & reasoning
2 days; No, include the $40 surcharge
The update replaces the time rather than adding 2 to 5. It also explicitly changes cost. Each source contributes a different part of the complete option.
06 / UNDERSTAND & APPLY
Verify every response component
A good solution includes the entire requested response. Check the number of rows, blanks or columns and verify each independently where appropriate. Do not assume a pattern such as one yes and two no responses.
For a table, preserve row identity when sorting and decide whether a claim is about counts, ranks or rates. One supporting row proves “some”; it cannot prove “all.”
ORIGINAL WORKED EXAMPLE
One table question, three judgments
Original table: team K produced 40 units in 8 hours; L produced 36 in 6; M produced 50 in 10. Mark True or False for each: (i) all teams produced at least 40 units; (ii) some team produced more than 5 units/hour; (iii) M produced the most units.
L produced 36, refuting (i).
Productivities are K 5, L 6 and M 5 units/hour; L supports (ii).
M’s 50 is greater than 40 and 36, supporting (iii). Three judgments are required for this one exercise.
Answer (i) False; (ii) True; (iii) True
ORIGINAL PRACTICE · 1
Two-Part: x+y=12 and x−y=4. Select x and y from {2,4,6,8,10}; one per column.
Reveal answer & reasoning
x: 8; y: 4
Adding gives 2x=16, so x=8 and y=4. Check both the sum 12 and difference 4; swapping the columns fails the second constraint.
07 / UNDERSTAND & APPLY
Make time decisions based on progress, not sunk effort
A long source set is not necessarily hard, and a short prompt is not necessarily easy. After identifying the task, ask whether your current approach is making progress. Repeatedly rereading without locating the missing relationship is a signal to change method.
During timed practice, rehearse a personal checkpoint plan that leaves time for completing remaining questions and allowed review. The useful rule is to stop an unproductive loop, make the best supported selection available and use the test interface’s permitted review features. No lesson can promise a universal seconds-per-format rule.
ORIGINAL PRACTICE · 1
You have computed one of two requested blanks and are unsure about the second. Is the question complete? Select Yes or No.
Reveal answer & reasoning
No
A correct first response does not supply the missing second response. Inspect its target and options, then select both before treating the question as complete.
08 / UNDERSTAND & APPLY
Use an error log to choose the next improvement
After practice, classify each error: interpretation, source selection, model, arithmetic, unit conversion, response completion or time management. Reworking only the arithmetic will not fix a source-definition error; reading faster will not repair faulty statement independence.
A final answer audit can be brief: target, units, denominator, domain, every component. In DS, add independent statement tests. In paired tasks, verify the joint constraints. In graphs and tables, distinguish exact values from estimates and observations from predictions.
KEEP THE BIG IDEAS
Quick revision
Identify the format and full response before calculating.
Use estimates for scale, exact values for close thresholds.
Track units and choose rounding from the real constraint.
Finish every requested component and review the cause of errors.
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