GMAT study guide

Work with ratios, percentages, rates, averages and number properties.

1. Translate every quantity into a consistent unit. Keep a rate, a total and a percentage base distinct.
2. Use fractions and simple numbers before doing long calculations. For averages, combine the totals and divide by the combined count; do not average two averages without their group sizes.
3. Estimate the result, solve without a calculator, then compare it with the estimate. Check whether the question asks for a value, a change or a percentage change.

Check your work: Percent changes use the original value as the denominator. Consecutive percentage changes multiply; they do not usually cancel.

Solve equations, inequalities and word problems while checking restrictions.

1. Define variables and record restrictions such as positive, integer or nonzero. Translate the relationship before manipulating it.
2. Look for a useful identity, common factor or substitution. You may only need an expression, rather than separate values for each variable.
3. Check all valid roots against the original equation. Reverse an inequality when multiplying or dividing by a negative number, and do not divide by an expression that could be zero.

Check your work: Squaring can introduce extra solutions. Verify them in the original equation rather than trusting the transformed equation alone.

Find a passage’s purpose, evidence and implications without adding outside facts.

1. Give each paragraph a short role: claim, evidence, objection or qualification. Track the author’s position separately from views they report.
2. For detail and inference questions, return to the relevant lines. Prefer the answer supported by their wording and scope, not a plausible statement about the wider topic.
3. For main-purpose questions, account for the whole passage. Reject choices that describe only one example, exaggerate certainty or reverse the author’s position.

Check your work: Words such as some, most, may and must change the strength of a claim. Keep the answer no stronger than the passage supports.

Identify assumptions, assess evidence and test the logic of an argument.

1. Identify the conclusion and the evidence offered for it. Then name the gap: causation, a comparison, a plan or a prediction.
2. Read the exact task. An assumption must support the reasoning; a weakening answer undermines it; an evaluation answer provides information whose possible outcomes matter.
3. For causal claims, check alternative causes and selection effects. For a necessary assumption, negate the candidate statement and ask whether the argument can still stand.

Check your work: A true statement about the topic can still be irrelevant. Explain which link in the argument your chosen answer changes.

Decide whether statements resolve a numerical or logical question.

1. Identify the exact question and its restrictions. Sufficiency means one definite value, or a definite yes or no—not necessarily a positive result.
2. Test each statement independently with the information in the question. Do not carry information from statement 1 into your test of statement 2.
3. Only combine the statements if neither works alone. To prove insufficiency, find two allowed cases that give different answers; do not merely say that a variable remains unknown.

Check your work: Test zero, negative numbers, fractions and boundary values whenever the question permits them. Logical sufficiency can also concern schedules, categories or rules without arithmetic.

Combine evidence from separate tabs, tables and written sources.

1. Preview the sources to see what each contains, then read the question. Write down the few fields or rules you actually need.
2. Join sources using the correct customer, date or item. Respect definitions: a pretax subtotal may differ from the total shown on an invoice.
3. Evaluate every statement separately. Use only supplied evidence, and distinguish “not supported” from a claim that has been positively disproved.

Check your work: Recheck the rule’s and/or logic. Do not stop after finding one favorable fact.

Sort a table and assess each statement against its data.

1. Read column labels, units and notes before sorting. Decide whether a claim concerns a total, a rank, a ratio or a change.
2. Use sorting to locate rows, but calculate derived quantities when needed. Sorting current sales cannot by itself rank percentage growth.
3. Answer every row of the response grid. When a claim says all or every, look for one counterexample rather than trying to justify an average trend.

Check your work: Use the starting value for percentage growth. For a multipart practice question, all response rows must be correct to earn the question’s mark.

Read chart scales and complete conclusions with the correct values.

1. Read the title, axes, scale and legend. Check whether values are amounts, percentages, cumulative totals or changes.
2. Translate the requested relationship into a calculation. Distinguish percentage points from relative percentage change and a ratio from a difference.
3. Complete every dropdown, then reread the whole statement. Use an estimate to catch a misplaced decimal or the wrong denominator.

Check your work: Do not infer exact values from a schematic graphic when its scale only supports an estimate. Follow the rounding precision requested.

Find a pair of answers that satisfies linked quantitative or verbal conditions.

1. Read both column headings and determine how the two answers are related. Keep the units and the order of the requested answers clear.
2. Solve the conditions together. In verbal tasks, test that the selected roles or statements can both be true under the supplied rules.
3. Choose one response in each column and verify the pair. Do not assume the two selections must be different unless the question requires it.

Check your work: Both parts must be correct for the practice question to score. Check the pair against every condition before moving on.