Data Sufficiency: Fundamentals
Jeff Sackmann / GMAT HACKS
January 2013
Contents
1 Introduction 2
2 Difficulty Level 3
3 Questions 4
4 Answer Key 19
5 Explanations 22
1
, Jeff Sackmann
www.gmathacks.com
1 Introduction
This document contains nothing but GMAT Data Sufficiency questions–100 of
them, to be exact. Data Sufficiency is a question type that you probably have
never encountered before you started studying for the GMAT, so it’s important
to master all the ins and outs of this type before attempting the exam.
As in all of my GMAT preparation resources, you’ll find these questions
indexed by difficulty.
For further, more specific practice, I have produced several other resources
that may help you. There is one 100-question ”Fundamentals” set that cov-
ers only Problem Solving questions, as well as several ”Fundamentals” sets on
topics such as Arithmetic, Algebra, Geometry, Number Properties, and Word
Problems.
Also, Total GMAT Math has dozens of chapters covering the content you
need to know for every type of GMAT problem. It’s one thing to master
an approach to Data Sufficiency, but that is only effective if you have already
conquered the math basics. If you find you are struggling with the mechanics
of these problems, your time is probably better spent with Total GMAT Math
than in doing dozens and dozens of practice problems, hoping to pick up those
skills along the way.
As far as strategy is concerned, there are dozens of articles at gmathacks.com
to help you with your strategic approach to Arithmetic questions. Most impor-
tantly, you should make sure you understand every practice problem you do. It
doesn’t matter if you get it right the first time–what matters is whether you’ll
get it right the next time you see it, because the next time you see it could be
on the GMAT.
With that in mind, carefully analyze the explanations. Redo questions that
took you too long the first time around. Review questions over multiple sessions,
rather than cramming for eight hours straight each Saturday. These basic study
skills may not feel like the key to GMAT preparation, but they are the difference
between those people who reach their score goals and those who never do.
Enough talking; there are 100 Data Sufficiency questions waiting inside. Get
to work!
2
Copyright 2008-13 Jeff Sackmann
www.gmathacks.com
, Jeff Sackmann
www.gmathacks.com
2 Difficulty Level
In general, the level 5 questions in this guide are 480- to 550-level questions. The
level 4 questions are lower than that, representing a broad range of difficulty
down to about a 380- to 400-level. Level 3 questions are included for skill
building purposes only; I hope you don’t see many of those on test day!
Very Easy (3)
001, 004, 028, 034, 045, 096, 097, 100
Moderately Easy (4)
002, 003, 005, 006, 008, 017, 020, 021, 022, 025, 026, 027, 029, 030, 032, 035,
036, 037, 038, 039, 040, 041, 043, 044, 048, 049, 053, 055, 056, 059, 061, 063,
066, 069, 071, 073, 074, 075, 076, 077, 078, 079, 080, 081, 082, 083, 086, 090,
091, 093, 094, 099
Medium (5)
007, 009, 010, 011, 012, 013, 014, 015, 016, 018, 019, 023, 024, 031, 033, 042,
046, 047, 050, 051, 052, 054, 057, 058, 060, 062, 064, 065, 067, 068, 070, 072,
084, 085, 087, 088, 089, 092, 095, 098
3
Copyright 2008-13 Jeff Sackmann
www.gmathacks.com
, Jeff Sackmann
www.gmathacks.com
3 Questions
Note: this guide contains both an answer key (so you can quickly check your
answers) and full explanations.
1. How much is 25 percent of a certain number?
(1) 200 percent of the number is 88.
(2) 150 percent of half the number is 33.
2. Is s greater than 0.66?
(1) s is less than 23 .
(2) s is equal to an integer divided by 100.
3. What is the value of the sum of a list of n even integers?
(1) n=7
(2) The sum of the numbers on the list is even.
4. Rodney and Eugene each received a bonus last year. Which
person’s bonus was larger, in dollars?
(1) Both Rodney’s and Eugene’s bonuses represented
15% of their annual salary.
(2) Rodney’s annual salary is 10% greater than Eugene’s.
5. If l and w represent the length and width, respectively, of the
rectangle above, what is the perimeter?
(1) The area of the rectangle is 120.
(2) The sum of two of the sides of the rectangle is 22.
6. What is the ratio of x to y?
(1) x is 4 more than twice y.
(2) x is 3 less than three times y.
4
Copyright 2008-13 Jeff Sackmann
www.gmathacks.com
Jeff Sackmann / GMAT HACKS
January 2013
Contents
1 Introduction 2
2 Difficulty Level 3
3 Questions 4
4 Answer Key 19
5 Explanations 22
1
, Jeff Sackmann
www.gmathacks.com
1 Introduction
This document contains nothing but GMAT Data Sufficiency questions–100 of
them, to be exact. Data Sufficiency is a question type that you probably have
never encountered before you started studying for the GMAT, so it’s important
to master all the ins and outs of this type before attempting the exam.
As in all of my GMAT preparation resources, you’ll find these questions
indexed by difficulty.
For further, more specific practice, I have produced several other resources
that may help you. There is one 100-question ”Fundamentals” set that cov-
ers only Problem Solving questions, as well as several ”Fundamentals” sets on
topics such as Arithmetic, Algebra, Geometry, Number Properties, and Word
Problems.
Also, Total GMAT Math has dozens of chapters covering the content you
need to know for every type of GMAT problem. It’s one thing to master
an approach to Data Sufficiency, but that is only effective if you have already
conquered the math basics. If you find you are struggling with the mechanics
of these problems, your time is probably better spent with Total GMAT Math
than in doing dozens and dozens of practice problems, hoping to pick up those
skills along the way.
As far as strategy is concerned, there are dozens of articles at gmathacks.com
to help you with your strategic approach to Arithmetic questions. Most impor-
tantly, you should make sure you understand every practice problem you do. It
doesn’t matter if you get it right the first time–what matters is whether you’ll
get it right the next time you see it, because the next time you see it could be
on the GMAT.
With that in mind, carefully analyze the explanations. Redo questions that
took you too long the first time around. Review questions over multiple sessions,
rather than cramming for eight hours straight each Saturday. These basic study
skills may not feel like the key to GMAT preparation, but they are the difference
between those people who reach their score goals and those who never do.
Enough talking; there are 100 Data Sufficiency questions waiting inside. Get
to work!
2
Copyright 2008-13 Jeff Sackmann
www.gmathacks.com
, Jeff Sackmann
www.gmathacks.com
2 Difficulty Level
In general, the level 5 questions in this guide are 480- to 550-level questions. The
level 4 questions are lower than that, representing a broad range of difficulty
down to about a 380- to 400-level. Level 3 questions are included for skill
building purposes only; I hope you don’t see many of those on test day!
Very Easy (3)
001, 004, 028, 034, 045, 096, 097, 100
Moderately Easy (4)
002, 003, 005, 006, 008, 017, 020, 021, 022, 025, 026, 027, 029, 030, 032, 035,
036, 037, 038, 039, 040, 041, 043, 044, 048, 049, 053, 055, 056, 059, 061, 063,
066, 069, 071, 073, 074, 075, 076, 077, 078, 079, 080, 081, 082, 083, 086, 090,
091, 093, 094, 099
Medium (5)
007, 009, 010, 011, 012, 013, 014, 015, 016, 018, 019, 023, 024, 031, 033, 042,
046, 047, 050, 051, 052, 054, 057, 058, 060, 062, 064, 065, 067, 068, 070, 072,
084, 085, 087, 088, 089, 092, 095, 098
3
Copyright 2008-13 Jeff Sackmann
www.gmathacks.com
, Jeff Sackmann
www.gmathacks.com
3 Questions
Note: this guide contains both an answer key (so you can quickly check your
answers) and full explanations.
1. How much is 25 percent of a certain number?
(1) 200 percent of the number is 88.
(2) 150 percent of half the number is 33.
2. Is s greater than 0.66?
(1) s is less than 23 .
(2) s is equal to an integer divided by 100.
3. What is the value of the sum of a list of n even integers?
(1) n=7
(2) The sum of the numbers on the list is even.
4. Rodney and Eugene each received a bonus last year. Which
person’s bonus was larger, in dollars?
(1) Both Rodney’s and Eugene’s bonuses represented
15% of their annual salary.
(2) Rodney’s annual salary is 10% greater than Eugene’s.
5. If l and w represent the length and width, respectively, of the
rectangle above, what is the perimeter?
(1) The area of the rectangle is 120.
(2) The sum of two of the sides of the rectangle is 22.
6. What is the ratio of x to y?
(1) x is 4 more than twice y.
(2) x is 3 less than three times y.
4
Copyright 2008-13 Jeff Sackmann
www.gmathacks.com
