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100 Hardest Data Sufficiency Questions [#permalink ]

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100 Hardest Data Sufficiency Questions

Are you familiar with the

GMAT Club's timer ? We have pulled timer results from our database and analyzed every question in the forum. Based on those results, we have compiled a list of the hardest questions in each of the question forums we have. Below I am presenting to you the top 100 questions from DS forum.

Data Sufficiency (DS) Rank Title Topics 1 Train A leaves New York for Boston at 3 PM and travels at Distance/Rate Problems 2 Bob and Wendy left home to walk together to a restaurant for Distance/Rate Problems 3 For integers a and b, if (a^3 a^2 b)^1/2 = 7, what is the Algebra 4 If, in the addition problem above, a, b, c, d, e, f, x, y, a Arithmetic 6 If a does not = 0, is 1/a > a/(b^4 + 3) Algebra/Inequalities 7 w, x, y, and z are integers. If z > y > x > w, is |w| > x^2 Inequalities/Absolute Values/Modules 8 w, x, y, and z are integers. If w >x>y>z>0, is y a common Number Properties/Divisibility/Multiples/Factors 9 In a group of 80 college students, how many own a car? (1) Overlapping Sets 10 In the correctly worked addition problem above, A, B, C, D Arithmetic/Number Properties 11 A rectangle is plotted on the standard coordinate plane Coordinate Geometry 12 If w>x>y>z>0, is z>4? Fractions/Ratios/Decimals/Inequalities 13 The average of 5 distinct single digit integers is 5. If Number Properties 15 If 20 Swiss Francs is enough to buy 9 notebooks and 3 Inequalities/Word Problems 16 Is |2a 3b| < |a b| + |a 2b| Absolute Values/Modules 17 If x and y are positive integers, what is the greatest Divisibility/Multiples/Factors 18 What is the perimeter of PQRS ? (1) x = 30 degree Geometry 19 If x, y, and z are positive integers such that x < y < z Number Properties/Divisibility/Multiples/Factors 20 How many subordinates does Marcia have? Combinations 21 At a restaurant, a group of friends ordered four main dishes Min/Max Problems 22 A certain salesman's yearly income is determined by a base Percent and Interest Problems/Word Problems 23 Is 1/(x-y) < y - x Algebra/Inequalities 24 Between 1980 and 1985, Pierres investment portfolio increas Percent and Interest Problems 25 A cube is made up of equal smaller cubes. Two of the sides Geometry 26 Of all the attendees at a dinner party, 40% were women. If Overlapping Sets 27 If x and y are positive integers is y odd? Number Properties/Algebra 28 If 5a=9b=15c, what is the value of a+b+c? Algebra 29 In a certain club, every member likes red wine or white wine Overlapping Sets 30 Jane can paint the wall in J hours, and Bill can paint the Work/Rate Problems/Word Problems 31 A set of nonnegative integers consists of Sequences 32 A committee of 2 people is to be formed from a group of 8 Probability 33 In the xy-plane, region R consists of all the points (x, y) Inequalities/Coordinate Geometry 34 If x is an integer, what is the value of x? Absolute Values/Modules 35 If the graph of y = x^2 + ax + b passes through the points Coordinate Geometry 36 If p, x, and y are positive integers, y is odd, and p = x^2 Divisibility/Multiples/Factors/Number Properties/Remainders 37 Is x^2*y^4 an integer divisible by 9 ? Number Properties/Divisibility/Multiples/Factors 38 A person inherited few gold coins from his father. If he Remainders/Word Problems 40 Laura sells encyclopaedias, and her monthly income has two Word Problems/Out of Scope - Too Hard 41 If x, y, and z are integers greater than 1, and Number Properties/Exponents/Powers 42 If n is an integer greater than 1 is 3^n-2^n divisible by 35 Number Properties/Exponents/Powers/Divisibility/Multiples/Factors 43 Is |x|<1? Inequalities/Absolute Values/Modules 44 Is A + B + C even? Number Properties 45 If a, b and c are integers such that b > a, is b+c > a Inequalities/Geometry 46 Reiko drove from point A to point B at a constant speed, and Distance/Rate Problems 47 If x^2 = y + 5, y = z - 2 and z = 2x, is x^3 + y^2 + z Divisibility/Multiples/Factors/Algebra 48 A Farey sequence of order n is the sequence of fractions Sequences 49 Last year, a certain company began manufacturing product X a Word Problems 50 At Western Springs School there are 150 total students Overlapping Sets 51 Is A positive? x^2-2x+A is positive for all x Ax^2+1 is Algebra 54 If for any positive integer x, d[x] denotes its smallest odd Divisibility/Multiples/Factors/Functions and Custom Characters 55 x is an integer and x raised to any odd integer is greater Exponents/Powers/Algebra 56 If x^2 = y + 5 , y = z - 2 and z = 2x , is x^3 + y^2 + z Algebra/Divisibility/Multiples/Factors 58 Six shipments of machine parts were shipped from a factory Fractions/Ratios/Decimals/Word Problems 59 Does the curve (x-a)^2 + (y-b)^2=16 intersect the y-axis ? Coordinate Geometry/Geometry 60 If a and b are positive integers, what is the remainder when Divisibility/Multiples/Factors/Number Properties/Remainders 61 If p and q are negative, is p/q > 1 Absolute Values/Modules/Inequalities 62 Is x^2 + y^2 > 100? Exponents/Powers/Algebra 63 If vertices of a triangle have coordinates (-2,2), (3,2) and Coordinate Geometry/Absolute Values/Modules 64 If xy 0, is x > y? (1) 4x = 3y (2) |y - x| = x - y Absolute Values/Modules/Inequalities 65 Is xy<0 ? (1) x^3*y^5/x*y^2 <0 (2) |x|-|y|<|x-y Absolute Values/Modules/Inequalities 66 If m and n are positive integers, is the remainder of Remainders 67 A right circular cone, twice as tall as it is wide at its Geometry 68 If the base score is between 10 and 99, the bonus is equal Word Problems/Arithmetic 69 Which of the two values 10^(-2) and 10^(-3), is x more close Arithmetic/Exponents/Powers 70 If x is positive, what is the value of |x 3| 2|x 4| + Inequalities/Absolute Values/Modules 71 A car dealership carries only sedans and SUVs Word Problems/Percent and Interest Problems 72 If a, b, and c are integers such that 0 < a < b < c < 10, is Divisibility/Multiples/Factors 73 If x < p < q < y. Is |q - x| < |q - y|? Inequalities/Absolute Values/Modules 75 A jar contains 8 red marbles and y white marbles. If Joan Probability 76 If x and y are negative numbers, is x<y? Inequalities 77 If m and n are positive integers, is m^n < n^m? Exponents/Powers/Inequalities 78 At a particular store, candy bars are normally priced at $1. Word Problems 79 Trains A and B left stations R and S simultaneously on two s Distance/Rate Problems 80 How many factors does the integer X have? Absolute Values/Modules/Algebra/Exponents/Powers 81 The sum of the integers in list S is the same as the sum of Statistics and Sets Problems 82 What does |2b| equal? Absolute Values/Modules/Algebra 83 A circle is drawn on a coordinate plane. If a line is drawn Geometry 84 If w, x, y and z are integers such that w/x and y/z are Number Properties 85 If x and y are non-zero integers and |x| + |y| = 32, what is Absolute Values/Modules 86 The integers m and p are such that 2<m<p, and m is not a Number Properties/Remainders/Divisibility/Multiples/Factors 87 If p is a positive odd integer, what is the remainder when p Remainders 88 Sequence S consists of 24 nonzero integers. If each term in Sequences 89 ax + by=10, ay + bx=12. which one is greater here, x or y ? Inequalities 90 Shaina's five-distinct-digit locker code is 5A48B. What Divisibility/Multiples/Factors 91 Is x > y ? (1) x^(1/2)>y (2) x^3>y Exponents/Powers/Roots/Inequalities 92 In a certain sequence, each term, starting with the 3rd term Sequences 93 |x|=|2y|, what is the value of x-2y? Absolute Values/Modules/Inequalities 94 If 6xy = x2y + 9y, what is the value of xy? Algebra 95 One kilogram of a certain coffee blend consists of x Word Problems/Mixture Problems 96 If a, b, and c are positive integers such that 1/a + 1/b = 1 Fractions/Ratios/Decimals/Inequalities 99 The Range of Set A is R. A number having equal value to R Statistics and Sets Problems 100 If x, y, and z are integers, and x < y < z, is z y = y Statistics and Sets Problems 101 In the table above is shown the percent reduction in the Percent and Interest Problems/Word Problems 102 Is the perimeter of triangle ABC greater than 20? (1) Geometry 103 What is the probability that rs=r? Probability 104 If zy < xy < 0, is | x - z | + |x| = |z|? Absolute Values/Modules/Inequalities 105 x and y are positive integers such that x=8y+12, what is the Number Properties/Divisibility/Multiples/Factors 106 Ashok and Brian are both walking east along the same path Distance/Rate Problems 107 If x, y and z are integers and xy + z is an odd integer, is Number Properties 108 Is (7x)^1/2 an integer? Roots/Number Properties 109 In a certain building, 1/5 of the offices have both a window Overlapping Sets

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Are any of these problems from GMAT prep? If there are any problems from GMAT prep, could you please highlight them with a different colour under the rank column.

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Hi, If possible can you make these topics hyperlink which redirects to concepts or may be question bank on same topic??? Just a thought. Thanks.

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Are these questions available in single file ?

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can we download all these probs in a single file?

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Would be great if you show these attachments in the first post..

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tnx lot for questions

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Thanks a lot Bunuel. Data Sufficiency is my weak area and this would surely help. Thanks!!

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It should be clear fairly quickly that neither statement alone is sufficient. For a lot of students, the phrase “well it could be anything”—the kind of massive generality that should be avoided on the GMAT—will follow them all the way to E without much thought or elbow grease.

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Thanks a lot Bunuel. I have a question about DS strategy . When you solve a DS question, you solve each data (1) and (2) wholy every time ?

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Great Collection. Although time taking Qs but very good to build stamina.

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Thanks Bunuel for sharing this wonderful collection.

DS is the toughest part IMO. From that working on tough ques is really amazing and challenging.

BTW, ques no 47 & 56 are repeated. can you add any other ques in any of that place ?

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