GMAT® Math | Official Guide 2017 | Data Sufficiency

Master data sufficiency strategies for the GMAT by indicating whether data are sufficient to solve, managing timing, and using a flowchart that covers about 95% of questions.

Learn the data sufficiency format: start with initial information and a question, evaluate one or two statements for sufficiency, and recognize that answer choices remain unchanged on test day.

Master data sufficiency by using a flowchart to derive two contradicting conclusions, then plug in convenient and nonterminating numbers to determine whether the data are sufficient.

Decode the true meaning of the data sufficiency answer choices for the GMAT, determine whether statement 1, statement 2, or both are sufficient, and choose the correct option quickly.

Use the ad-bce split to determine data sufficiency in data sufficiency questions. Simplify the initial information, assess what is needed, and apply the flowchart to test statements alone or together.

Apply the data-sufficiency flowchart to test each statement or their combination, proving insufficiency by deriving two different conclusions; for decimals, ensure the denominator has only powers of two and/or five.

Learn to solve a GMAT data sufficiency question in 30 seconds by factoring 5(a+2p), evaluating each statement's sufficiency, and recognizing when a single statement is enough.

Master data sufficiency in geometry by stretching the diagram to see if the target angle changes, then assess statements 1, 2, or their combination to fix alpha.

Determine the number of tea drinkers among 60 diners who drink coffee or tea. Assess statements 1 and 2 for sufficiency, noting totals, contradictions, and rules.

Understand data sufficiency in GMAT math by analyzing whether given distance and time suffice to determine a car’s average rate, without performing unnecessary calculations.

Analyze how one or two statements on a quadratic equation determine a single value for x, illustrating sufficiency and common pitfalls in data-sufficiency questions.

Identify data sufficiency strategies for GMAT math: use flow chart to assign a or d for sufficiency and b, c, or d for insufficiency, aiming for two contradictory conclusions.

Solve data sufficiency geometry questions in real time using external angles and alpha plus beta logic. Learn to test sufficiency by stretching figures to extremes.

Evaluate data sufficiency problems by breaking verbal expressions into manageable parts, analyzing overlap between chemistry and biology, and using a number line to test for sufficient information and contradicting conclusions.

This lecture analyzes a data sufficiency problem with two linear equations, explains why a single equation may be insufficient, and applies divisibility checks, visibility rules, and a graphical solution.

Explore data sufficiency in GMAT style questions by using a fraction tree to relate earnings, savings, expenses, and taxes, showing when a relative expression and a quantity yield sufficiency.

Sketch on the x y plane to test triangle q p r is right. Together the statements show q p perpendicular to p r, yielding a 90-degree angle.

Combine the total of 24 marbles with red count and white probability to determine blue marbles; deduce blue equals 4 and probability of blue is 1/6.

Analyze GMAT data sufficiency for a rectangle that forms a square with X = y = 1 and right angles; conclude that statements combined yield the correct choice C.

Solve data sufficiency by modeling a tank's net rate as inlet rate minus outlet rate, using statement 2 alone to determine the combined rate of 6 gallons per minute.

Apply a quick percent rule to treat percent as division by 100. Read relative expressions as linked to the directly related quantity to assess sufficiency without solving.

Apply root-exponent tricks to data-sufficiency questions: isolate the root expression and raise both sides to the appropriate power to remove roots, as shown in question 240.

Spot a data-sufficiency item as arithmetic by noting a constant difference, then apply a_n = a1 + (n-1)d to assess sufficiency when combining statements.

Apply arithmetic sequence reasoning to compute total seats—first term 18, common difference 2, across 27 rows—and assess data-sufficiency for the statements.

Analyze a GMAT® data sufficiency question on which is greater, u^v or v^u, by using the equilibrium of powers and plugging numbers to test sufficiency.

Analyze a GMAT data sufficiency problem about high and low prices from the official guide 2017. Practice testing statements by plugging in numbers to determine the range and sufficiency.

Explain data sufficiency for price differences among greatest, least, and middle values, showing how single statements are insufficient and how combining them can yield two contradicting conclusions.

Examine data sufficiency for whether R times W equals zero in a GMAT problem, showing that each statement alone is insufficient and even both together may not determine the result.

Multiply by xy in this data sufficiency problem, since xy is nonzero, yielding xy equals 1 from statement 1 and from statement 2.

Solve a GMAT data sufficiency double-overlap problem by modeling two ownership groups and their 15-person overlap within a 50-person total, showing neither group size is fixed by partial data.

Analyze data sufficiency for w using negative exponents and root extraction, including even/odd root nuances; statement 1 yields w = 2, statement 2 yields w = 2, confirming answer D.

Identify this as a compound interest data-sufficiency problem and show that a single accurate quantity, or either statement alone, suffices to compare third-year and first-year interest, yielding answer D.

Calculate average speed for a 50-mile trip with 30 miles at 60 mph and 20 miles at 50 mph, then confirm statement two suffices (total time 54 minutes).

Learn to simplify data in GMAT data-sufficiency questions by canceling constants to reveal T=6, and apply this to see that T^3=216 alone suffices to determine T.

Apply data-sufficiency reasoning to a GMAT official guide 2017 problem about total charge with parts, labor, and tax, showing how to deduce labor cost from one equation.

Explore a data-sufficiency method for GMAT by mapping hardcover and paperback fiction and nonfiction on a number line, evaluating statements for sufficiency without diagrams.

Examine data sufficiency for an expression greater than zero in the GMAT data sufficiency context. Use age and W as statements, plug in numbers, test for contradictions, and determine sufficiency.

Analyze data sufficiency for a GMAT ratio problem from the official guide 2017, where statements 1 and 2 establish girls to boys and test sufficiency to determine the ratio.

This GMAT data-sufficiency lecture explains solving an arithmetic-sequence problem by using a known term and the common difference to find other terms, and evaluates statements 1 and 2.

Examine a data-sufficiency problem on donations expressed as a percent of annual profits, showing that combining two statements yields a definite yes/no on whether the donation exceeds ten thousand.

Explore solving a GMAT data sufficiency question with ratios and midpoints, modeling segments as x, 2x, and 4x to compare CD and DB, and determine when statements are sufficient.

Analyze a data-sufficiency problem on a square and circle, using inscribed configurations and fixed area ratios. Show that either statement alone determines the square’s area, with the fourth choice correct.

Assess data sufficiency for the slope of k by evaluating statements 1 and 2, sketching the data, noting contradictions, and concluding that positive versus nonpositive slope makes the data insufficient.

Combine the width and height statements to determine feasibility, and learn why the GMAT data-sufficiency yes-no question yields answer C in the truck cross-section.

This lecture covers data sufficiency in a GMAT interest problem, clarifying simple versus compound interest and when two statements leave the answer indeterminate.

Determine whether at least 60 percent of students walk by applying a 2:1 walking to non-walking ratio and converting to 66 and two thirds percent, a yes-no data-sufficiency question.

Explore a data-sufficiency GMAT problem where profit grows not linearly with units sold, examining 380,000 and 350,000-unit cases to determine thresholds above 4 and 5 million.

Explore data sufficiency strategies for GMAT style questions, using odd and even reasoning, plug-in checks, and concise quadratic identities to determine which statements suffice.

Analyze how rate, time, and pay relate via units and inverse proportionality, determining hours after a rate increase in a data sufficiency context.

Explore a GMAT data sufficiency problem about whether a fraction is less than 9/11, using multipliers and sign rules. Compare fractions and decimals to show that statement two is sufficient.

Analyze data-sufficiency strategies for a GMAT problem by applying precise rounding rules to the nearest tenth, hundredth, and thousandth, and determine when each statement suffices to solve for t.

Apply odd–even reasoning and number plugging to data-sufficiency questions on sums and products, using 0, 1, 2, 3 to determine when a factor is even and assess sufficiency.

Analyze data sufficiency by testing two statements with two variables, using x+y=15 and square roots to derive contradictory conclusions, showing only together are sufficient, yielding answer C.

Explore a data sufficiency GMAT question linking fuel consumption to speed with the equation kv^2, determine when it equals one third, and show that either statement 1 or 2 suffices.

Analyze how t affects the expression, showing that even-root extractions yield plus or minus results while odd-root extractions are unique, impacting data-sufficiency conclusions.

Explore data sufficiency in GMAT style by evaluating cotton quantities and per-jacket fabric requirements to determine if more than 1,050 jackets can be produced.

Examine common factors of 18 and 24 to determine x in a data sufficiency problem; statement 1 is sufficient, statement 2 is insufficient, so the answer is a.

Learn data sufficiency techniques to compute the discount percent when the before price is 25 percent greater than the after price.

Analyze a data sufficiency question by simplifying to compare bases with negative powers, then test statements using values like 0 and 1 to determine sufficiency.

Explore a data sufficiency GMAT problem where total cost equals a fixed sum plus a charge beyond 420 minutes. Statement 1 is not sufficient; statement 2 is sufficient; answer B.

Simplifies inequalities like x < 2y to teach data-sufficiency for GMAT math, tests values, and shows that statement 1 may be insufficient while statement 2 clarifies the solution.

Digest data sufficiency techniques apply to a two-statement GMAT problem about attendance percentages, showing that neither statement alone nor both together provide enough information, with emphasis on distribution and breakdowns.

This lecture shows solving a GMAT data-sufficiency problem using the average to total items, applying 6% tax on prices over 80, and why statements 1 and 2 yield insufficient data.

This data-sufficiency walkthrough demonstrates simplifying the problem by substituting P and Q, using benchmarks to compare Q to 221, and evaluating statements 1 and 2 for sufficiency.

Solve a data sufficiency problem on offers from two companies, using probability rules for or (sum) and (product), to determine P(both) and arrive at option C.

Explore standard deviation and its relation to the average in a GMAT data sufficiency problem, showing that statement two alone suffices when all nests hold equal eggs.

Use a top distance and bottom rate visual to apply distance equals rate times time; convert units and compare against 75 seconds to judge data sufficiency for GMAT question 285.

Knowing w + l = 22 with a variable border cannot fix the rug’s interior area; different shapes give 32 or 80, so the data are insufficient.

Assess data sufficiency in a GMAT probability problem by analyzing blue and red card counts to determine the probability of red or white.

Identify that z appears in xz and yz, making a fraction potentially undefined. Use the common factor and statement 1, 2x+1=3, to test sufficiency of x, y, and z.

Analyze angle relationships in a parallelogram with parallel lines, using supplementary angles to deduce x, and verify data sufficiency from two statements.

analyzes a data sufficiency problem about cost, markup, and selling price, illustrating that a 25-dollar markup on 100 yields 125 selling price and a 20 percent relation to selling.

Explore data sufficiency for double overlap questions, using two statements to determine the exact overlap between relief and side effects, and avoiding Venn diagrams.

Express different bases as powers of the same base, set 2^(x+y) = 2^30 to get x+y=15, then combine the two statements to confirm data sufficiency for x and y.

Learn to determine data sufficiency for a product's sign by testing statements, using number plugging and even-power properties, as shown in the GMAT official guide 2017 question 293.

Analyze a GMAT data sufficiency problem with -3 or +2 games from 100 to 104; apply the least common multiple of 3 and 2 to test swings; statements are insufficient.

Analyze data sufficiency on GMAT tests by breaking down complex statements, analyzing totals and left counts, evaluating a 5 and 3 left scenario, and using two statements to determine sufficiency.

Assess data sufficiency for a GMAT problem on whether a glass sheet covers a table top. Examine table dimensions, glass area, and how combining statements changes coverage conclusions.

Explore a data sufficiency GMAT question about college graduates versus non-graduates, using a ratio and a total of 80 to solve for x, yielding x=20 and non-graduates=60.

Learn to solve GMAT data sufficiency for the tenth digit by testing statements separately and together, using numbers to check if the digit must be 2 or 3.

Use data-sufficiency reasoning with rates X, Y, and Z to decide whether Z is the greatest; individual statements are insufficient, but together they confirm Z's greatest status.

Explore GMAT data sufficiency by testing sums of integers with possible negatives and positives, showing that combining statements yields a unique zero sum, option C.

Analyze data-sufficiency for inequalities by plugging in numbers and testing contradictions, using two contradictory conclusions. Conclude that statement 2 is sufficient and statement 1 is insufficient, with the answer B.

Explore data sufficiency for double overlap questions using a number-line approach to find the overlap between groups, illustrated by 17 directors and groups K and R.

Learn how to compute a store's profit as a percent of cost using variables x and y, ratios, and data-sufficiency reasoning with statements one and two.

Explore a data sufficiency question with four distinct odd integers in consecutive order summing to 64, revealing that D is the greatest and the others are D-2, D-4, and D-6.

Apply data sufficiency techniques in GMAT math to bound x and y using fractions and percentages, and learn how combining statements yields clear conclusions.

Learn data sufficiency strategies for GMAT math by using relative expressions and percent increases to derive the May 30 balance from the May 1 balance, verifying sufficiency.

Plug in convenient numbers to test data sufficiency for x and y under the positive and inequality constraints, using symmetry around ten and variable isolation.

Demonstrates data-sufficiency reasoning for coat and sweater discounts, showing how to test statements by plugging numbers, using a 100 base, and concluding when data are insufficient.

Demonstrate how two linear equations resolve a two-variable ride-cost problem in a data-sufficiency context, where neither statement alone is sufficient but combined they become solvable.

Explore data sufficiency with two squares of consecutive integers and their constant differences. Use intuition and memorized square differences such as 144-169 and 169-196 to determine sufficiency without full calculation.

Explore GMAT data sufficiency on percent change in net income. Show how 4% gross income rise and 15% deductions rise illustrate insufficient statements and contradictions.

Analyze a GMAT data-sufficiency problem on the ratio of students to district size, showing that combining statements can still be insufficient due to a 10,000 difference.

Examines data-sufficiency using a two-variable gift certificate problem with 10 and 50 dollar certificates. Illustrates how integer constraints and cost totals can make x+y not unique.

Solve data-sufficiency tasks by plugging in convenient numbers to derive two contradictory conclusions, then assess statement 1, statement 2, or their combination.

Explore how to test data sufficiency by evaluating statements separately, plugging in convenient numbers, and combining them to determine sufficiency for distance and squared relationships, including negative or positive distances.

Learn to determine how many triangles exist from a set of points by considering shape and number. Use combinations to compute possibilities, as five points yield ten triangles.

The lecture demonstrates data-sufficiency strategies for a GMAT price comparison problem: show that neither statement alone suffices, but combining percent-based amounts yields the needed comparison.

Explore data sufficiency on rounding rules, statements 1 and 2, and plug-in methods to decide if unrounded values are at least 0.5.

The lecture analyzes GMAT data sufficiency question 320 from the official guide 2017, showing MQ to Q ratio 1:2 and that statement 1 is sufficient.

Map the scholarships and loans groups on a number line to find their overlap and the neither portion, then test each statement's sufficiency using the given percentages.

Analyze a data sufficiency problem about three shirt prices, where the most expensive shirt z exceeds 30, and determine sufficiency of statements 1 and 2, concluding statement 2 is sufficient.

Explore a data-sufficiency problem with coins b and c, using b = 1.5 c and a total between 21 and 28; deduce c equals 10 by combining statements.

This lecture explains data sufficiency in GMAT math by comparing capacity x times y to 500 calls, and shows statement 1 is sufficient while statement 2 is not.

Solve a GMAT data sufficiency problem by analyzing percent shares and a 40 percent revenue increase for jazz and blues; use statement 2 to derive a solvable equation.

Model distance problems by marking distance above a line and using rates x and y; total distance is 2x+3y and average speed is (2x+3y)/5.

Analyze data sufficiency for a GMAT question by testing each statement for contradictions, then combine statements to determine if a unique x exists, using integer and square root conditions.

Use two equations with three unknowns for k, m, and p to solve a GMAT data sufficiency rate problem by subtracting equations, finding k's time as 72 minutes.

apply data-sufficiency to a horizontal cylindrical tank problem; show gasoline volume is half the tank’s volume when depth equals the radius, using cylinder volume formula and right-triangle geometry.

Examine data sufficiency using opposite numbers and distance to zero, testing statements about q, s, r, and t to determine when r is closest to zero.

Master weighted-average data sufficiency with two-group cases by applying inverse ratios, estimating how the overall average falls toward the larger group, and judging sufficiency from conflicting statements.

Solve a data sufficiency problem with two equations and two integer variables by extracting common factors, evaluating statements for sufficiency, and avoiding unnecessary arithmetic.

Analyze a GMAT data-sufficiency problem about a pyramid donation scheme, modeling donors with n and a 500-dollar contribution, using an^2+an to total; statement 1 yields n = 15.

Explore the area of a triangle as base times height, including internal and external heights, and how perpendiculars to a side or its extension impact GMAT data-sufficiency questions.

Explore data sufficiency on a GMAT coordinate plane problem by testing equidistance from two points, using isosceles triangle reasoning and the line y = a − 3.

Examine a GMAT data-sufficiency weighted-average problem, showing why four data items are needed and why 120 and 126 are insufficient to find the fifth value, via inverse ratios.

Learn to use the units digit and place-value breakdown to plug in convenient numbers for data-sufficiency questions, showing that both statements alone are sufficient.

Learn how to solve data sufficiency questions with two bases and exponents, simplify power-of-a-power scenarios to x+y=16, and assess statements about x and y using linear equations.

Examine a data sufficiency GMAT problem with a basic amount plus 5 percent commission and 10 percent of sales. Use statements to form a solvable single equation with one unknown.

Explore a GMAT data sufficiency question on two simple-interest investments totaling 16,000, and show how statements alone fail but combined yield x, using ratios to relate x and y.

Review data sufficiency tactics for GMAT math using a bakery word problem, showing how a single equation with two variables yields a value and tests statement sufficiency.

Explore how data sufficiency questions use ratio reasoning in isosceles right triangles to compare areas. The lecture demonstrates checking extreme cases and combining statements to determine sufficiency.

Decide if a fraction terminates by reducing it and checking the denominator for only powers of 2 and 5; a factor of 100 for r suffices.

This lecture illustrates data-sufficiency tactics from the official guide 2017, question 344, using factoring and plugging values with x and y, showing statements 1 and 2 can be sufficient.

GMAT data sufficiency principles show how to compare positive r and s by simplifying inequalities and using cross multiplication; either statement alone suffices to show r < s.

Analyze a data-sufficiency problem on k between 57 and 65, where k is odd and k+1 is divisible by 3, yielding multiple possible values and making the data insufficient.

Practice data sufficiency for prime status of x using 3x+1 and 5x+1, testing values to expose contradictions and noting primes must pass factors up to the square root.

Assess data sufficiency for a GMAT math problem by analyzing the median of an ordered set. Combining statements yields a unique median of 10, making option C the correct choice.

Analyze a GMAT data sufficiency problem to determine x+y using integer constraints, single-value deduction, and the sufficiency of statements, concluding x+y equals 7 with consistent reasoning.

explores data sufficiency for rate comparisons by using time equals distance over rate, cross-multiplication with inequalities, and how adding the same amount to numerator and denominator affects fractions.

The lecture demonstrates data-sufficiency for a GMAT data problem about mortgage, taxes, and insurance totaling 12000, guiding students to identify sufficiency through variable relationships and percentage hints.

This GMAT data sufficiency lecture shows how to simplify an inequality by multiplying and dividing by a positive fraction, proving statement 2 is sufficient (option b).

Resolve a data-sufficiency problem on overlapping groups: show that 20 percent of x equals 30 percent of y with both statements, proving x is greater than y.

Learn how the average of consecutive even integers equals the middle value, and how this midpoint principle determines data-sufficiency in GMAT problems with Q and R.

Explain how the bracket of x represents the least integer greater than or equal to x and how rounding up informs data sufficiency, with the answer C.

analyze data sufficiency with two statements: x+y positive, and y^x negative; combined, x is positive and y is negative, implying x>y. review negative powers and solving with both statements.

Solve data sufficiency for a quadratic with roots x1 and x2, using sum and product to show the product of the roots equals a c; conclude that c<0 determines sufficiency.

An l-shaped geometry problem uses rectangles to form a quadratic for x from area 189. It demonstrates data sufficiency: statement 1 is sufficient, statement 2 is not.

Apply a ratio with shirts, dresses, and jackets to determine the total items in the closet, then use integer constraints and statements to establish sufficiency.

Explain how sector area relates to circle area through the central angle, using sector area = (angle/360) × circle area; statement 1 is sufficient, statement 2 is insufficient.

Learn how to solve GMAT data sufficiency questions using root extraction rules, benchmark cube roots, and determine x with a single root, such as x < -3.

Explore data sufficiency in GMAT questions by determining how many cans fit into a carton from cylinder and carton dimensions, and evaluate whether combined statements yield enough data.

Analyze a data sufficiency GMAT question from the official guide using row and column rules to deduce three appears once. Conclude data are sufficient, with the correct answer D.

Shows how to solve a two-group mixture data-sufficiency using weighted averages, proving statement 1 is insufficient and statement 2 alone suffices, guided by x, y, and price per kilogram.

Explore data sufficiency on the GMAT with k and m, counting factors of two, and determine why statement 1 is insufficient while statement 2 is sufficient by plugging in numbers.

Evaluate data sufficiency in a GMAT speed problem: compute average rate from 460 miles in four hours, and assess statements 1 and 2 for sufficiency.

Discover how standard deviation measures how far numbers differ from the average, and how GMAT data sufficiency uses these ideas, including median, to test statements.

In this GMAT data sufficiency lecture, learn how median and average relate to a set of house prices. Statement two sets Jane’s price at 120, making the median 120.

explains using parity to decide data sufficiency for x and y, showing an even product comes from at least one even factor, and analyzes statements 1 and 2.

Apply midsegment and area ratio concepts to a triangle data-sufficiency problem; use a 1:4 area relationship and a 32 area to deduce the full triangle, showing statement 1 suffices.

Explore data sufficiency with a 2:3:4 ratio, showing statements can be insufficient and combined statements may still lack a unique answer, highlighting the need to plug in numbers.

Form a fraction tree to solve fraction-of-a-fraction and percent-of-a-percent questions, using two thirds and three quarters to determine the total and number of non-managers, proving sufficiency of each statement.

Explore circle data-sufficiency using similar shapes: a 1:2 circumference ratio implies a 1:4 area ratio, allowing quick deduction of k's area from g, given area or circumference data.

analyze a data sufficiency problem with an invented operation: w = max(20, z); determine min(10, w). show that either statement 1 or statement 2 can be sufficient.

Discover how to determine the median in data sufficiency problems by using ordered sets and shelf analogies, testing statements for sufficiency, and combining to reach a single conclusion.

analyze circle geometry to determine the radii and areas of a large and a small circle using data sufficiency statements 1 and 2, and compare diameter relationships.

Explore data sufficiency on a GMAT question about time, distance, and rate. Use a fast method, test statements 1 and 2, and show how contradictions determine sufficiency.

Learn that in an ordered set with constant difference, the average equals the median, and evaluate data-sufficiency statements showing each condition can determine the correct choice.

Solve two equations to locate the intersection of the lines, then substitute the coordinates into the third line to find B. Both statements alone are sufficient.

Use the perimeter relation between the thick outer line and the inner triangle to test data sufficiency; statement one is sufficient, while statement two is insufficient.

This lecture clarifies data sufficiency with sets S and T, where T lies in S, and uses range comparisons to determine sufficiency; combining statements yields contradictory conclusions.

Model percent changes in rents using a base value and solve inequalities to test data sufficiency. The lecture demonstrates that statement 2 is sufficient, emphasizing percent changes and base reasoning.

Solve a data-sufficiency question on a right triangle using Pythagoras and symmetry to show that statements 1 and 2 together suffice in an isosceles right triangle.

The lecture compares algebraic and coordinate geometry methods for the GMAT data sufficiency problem 2x+3y≤6, showing how statements alone or together may fail and the value of sketching lines.

This lecture covers data sufficiency for a box volume with three variables—width, height, and length—using equations to determine volume. It demonstrates proportional reasoning and algebraic elimination to reach the volume.

Learn data sufficiency strategies for division questions by choosing convenient numbers, such as 60, to test shipment values and determine whether shipment three belongs to truck one.

Learn practical strategies for GMAT data sufficiency questions, using vertical layouts, convenient digit assignments, and carry-over reasoning to test sufficiency without exhaustive enumeration.

Explore data-sufficiency reasoning for a GMAT question by solving overlaps between favorable and not-favorable voter groups using a number-line approach, identifying when statements 1 or 2 are sufficient.

Examine divisibility in GMAT data sufficiency using two statements about n and m, highlight prime 13, and determine when statement 1 or 2 suffices to prove n divisible by m.

Combine two percent statements to deduce the median project load; the 50th employee has three projects, so the data are sufficient, making option C correct.

Explore GMAT data sufficiency by linking profit to revenue and expenses, then bound unit sales using price per unit and total revenue through inequalities.

Explain data sufficiency by tracing balance changes, define range as the difference between highs and lows, and determine the tipping point where May’s plus 120 shifts to June’s minus 50.

This lecture explains data sufficiency with a 15-number set totaling 60 and the any-three-sum-to-12 rule, using contradictions, averages, and standard deviation ideas to determine if all items are identical.

Evaluate data sufficiency by testing statements 1 and 2 about numbers around 75. Analyze averages, potential contradictions, and the role of standard deviation to determine sufficiency.

Analyze data sufficiency with two statements about commissions and sales, showing neither alone nor together yields enough information due to relative expressions and an unknown sum.

Explain how a right-triangle data-sufficiency problem from the GMAT official guide 2017 uses area and pythagorean relations to yield three equations, showing each statement alone is sufficient.

This lecture demonstrates using simple benchmarks and a weighted average to decide if the overall GMAT data-sufficiency problem's average is under 120, analyzing two statements to determine sufficiency.

Apply data-sufficiency reasoning to a GMAT problem, using scientific notation and orders of magnitude to deduce a single positive value for k, with even-root extraction and benchmarks for estimation.

Analyze data-sufficiency statements about a negative x, its absolute value, and powers to decide whether the right side exceeds the left in the GMAT official guide 2017 data sufficiency question.

learn data sufficiency strategies for GMAT questions by applying the 360-degree rule for external angles in polygons, and determine sums like x and y from single or combined statements.

Apply radical elimination and even power rules to inequalities, using positivity of roots, to determine data sufficiency; show statement one suffices while statement two fails by counterexample.

Explore a data-sufficiency GMAT problem where production is directly proportional to a constant ratio. Statement 1 is insufficient, while statement 2 is sufficient.

Explore data sufficiency strategies for GMAT, distinguishing when statements yield a definite value or are insufficient, using plugging in, contradictions, and ensuring no cross-contradictions.

Analyze a data sufficiency question with two equations in x and t, showing that statement 1 suffices while statement 2 does not.