id
stringlengths
12
47
source_name
stringclasses
4 values
source_file
stringclasses
4 values
source_type
stringclasses
2 values
page_start
int64
1
733
page_end
int64
1
733
topic_guess
stringclasses
12 values
text
stringlengths
8
3.21k
GMAT Club Math Book 2024 v8_p97_c1
GMAT Club Math Book 2024 v8
GMAT Club Math Book 2024 v8.pdf
pdf
97
97
statistics
Properties ; only if all elements in a set is equal; Let standard deviation of be and mean of the set be : Standard deviation of is . Decrease/increase in all elements of a set by a constant percentage will decrease/increase standard deviation of the set by the same percentage. Standard deviation of is . Decrease/incr...
GMAT Club Math Book 2024 v8_p98_c1
GMAT Club Math Book 2024 v8
GMAT Club Math Book 2024 v8.pdf
pdf
98
98
statistics
if a new element is added to set and standard deviation of a new set is , then: 1) if 2) if 3) if 4) is the lowest if Tips and Tricks GMAC in majority of problems doesn't ask you to calculate standard deviation. Instead it tests your intuitive understanding of the concept. In 90% cases it is a faster way to use jus...
GMAT Club Math Book 2024 v8_p99_c1
GMAT Club Math Book 2024 v8
GMAT Club Math Book 2024 v8.pdf
pdf
99
99
statistics
means that all elements strictly related to each other. If we shift the set by adding or subtracting any integer, does it change standard deviation (average deviation of elements from the mean)? No. One thing we should know is the number of elements in the set, because the more elements we have the broader they are dis...
GMAT Club Math Book 2024 v8_p100_c1
GMAT Club Math Book 2024 v8
GMAT Club Math Book 2024 v8.pdf
pdf
100
100
general
covers 68% of data covers 95% of data covers 99% of data m − σ < x < m + σ m − 2σ < x < m + 2σ m − 3σ < x < m + 3σ GMAT Club Math Book 100
GMAT Club Math Book 2024 v8_p101_c1
GMAT Club Math Book 2024 v8
GMAT Club Math Book 2024 v8.pdf
pdf
101
101
statistics
Practice Questions Easy: 1. https://gmatclub.com/forum/the-data-set ... 76313.html 2. https://gmatclub.com/forum/which-of-the ... 31485.html 3. https://gmatclub.com/forum/a-certain-ch ... 43982.html 4. https://gmatclub.com/forum/if-d-is-the- ... 93979.html 5. https://gmatclub.com/forum/for-a-certai ... 28661.html 6. ht...
GMAT Club Math Book 2024 v8_p101_c2
GMAT Club Math Book 2024 v8
GMAT Club Math Book 2024 v8.pdf
pdf
101
101
word_problems
forum/if-j-k-m-n-a ... 72294.html 9. https://gmatclub.com/forum/which-of-the ... 90680.html 10. https://gmatclub.com/forum/the-list-abo ... 93102.html Page 1 of 1 All times are UTC - 8 hours [ DST ] GMAT Club Math Book 101
book 2_p3_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
3
3
word_problems
MANHATTAN PREP GMAT Advanced Quant GMAT STRATEGY GUIDE This supplemental guide provides in-depth and comprehensive explanations of the advanced math skills necessary for the highest-level performance on the GMAT. GMAT® is a registered trademark of the Graduate Management Admissions Council™. Manhattan Prep is neither e...
book 2_p4_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
4
4
general
Table of Contents
book 2_p5_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
5
5
strategy
GMAT Advanced Quant Cover Title Page Copyright Instructional Guide Series Letter Introduction In This Chapter... A Qualified Welcome Who Should Use This Book Try It Yourself The Purpose of This Book An Illustration Learning How to Think Plan of This Book Solutions to Try-It Problems Part 1: Problem Solving and Data Suf...
book 2_p6_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
6
6
algebra
Principle #2: Never Rephrase Yes/No as Value Principle #3: Work from Facts to Question Principle #4: Be a Contrarian Principle #5: Assume Nothing Problem Set Solutions Chapter 4: Data Sufficiency: Strategies & Tactics In This Chapter... Chapter 4 Data Sufficiency: Strategies & Tactics Advanced Strategies Advanced Guess...
book 2_p7_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
7
7
sequences_patterns
Rubber Band Geometry Baseline Calculations for Averages Number Line Techniques for Statistics Problems Problem Set Solutions Chapter 8: Hybrid Problems In This Chapter... Pop Quiz! Hybrid Problems Identify and Sequence the Parts Where to Start Minor Hybrids Problem Set Solutions Part 3: Practice Chapter 9 Workout Sets ...
book 2_p8_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
8
8
general
Workout Set 7 Solutions Workout Set 8 Workout Set 8 Answer Key Workout Set 8 Solutions Workout Set 9 Workout Set 9: Answer Key Workout Set 9 Solutions Workout Set 10 Workout Set 10 Answer Key Workout Set 10 Solutions Workout Set 11 Workout Set 11 Answer Key Workout Set 11 Solutions Workout Set 12 Workout Set 12 Answer ...
book 2_p9_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
9
9
coordinate_geometry
Acknowledgements A great number of people were involved in the creation of the book you are holding. Our Manhattan Prep resources are based on the continuing experiences of our instructors and students. The overall vision for this edition was developed by Chelsey Cooley, who determined what new areas to cover and who w...
book 2_p10_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
10
10
word_problems
GMAT® STRATEGY GUIDES GMAT All the Quant GMAT All the Verbal GMAT Integrated Reasoning and Essay STRATEGY GUIDE SUPPLEMENTS Math Verbal  GMAT Foundations of Math GMAT Advanced Quant GMAT Foundations of Verbal
book 2_p11_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
11
11
word_problems
January 7, 2020 Dear Student, Thank you for picking up a copy of Advanced Quant. I hope this book provides just the guidance you need to get the most out of your GMAT studies. At Manhattan Prep, we continually aspire to provide the best instructors and resources possible. If you have any questions or feedback, please d...
book 2_p12_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
12
12
word_problems
particular thanks to instructors Stacey Koprince and Ben Ku for their content contributions. Finally, we are indebted to all of the Manhattan Prep students who have given us excellent feedback over the years. This book wouldn’t be half of what it is without their voice. And now that you are one of our students too, ple...
book 2_p13_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
13
13
general
Introduction
book 2_p14_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
14
14
fractions_decimals_percents
In This Chapter... A Qualified Welcome Who Should Use This Book Try It Yourself  The Purpose of This Book An Illustration Learning How to Think Plan of This Book Solutions to Try-It Problems
book 2_p15_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
15
15
coordinate_geometry
Introduction A Qualified Welcome Welcome to GMAT Advanced Quant! In this venue, we decided to be a little nerdy and call the introduction Chapter 0. A er all, the point (0, 0) in the coordinate plane is called the origin, isn’t it? (That’s the first and last math joke in this book.) Unfortunately, we have to qualify ou...
book 2_p16_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
16
16
fractions_decimals_percents
Who Should Use This Book You should use this book if you meet the following conditions: If you match this description, then please turn the page. You have achieved a scaled score of at least 47 (out of 51) on the Quant section of either the Manhattan Prep practice test or the official practice computer-adaptive test (CA...
book 2_p17_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
17
17
fractions_decimals_percents
If you don’t match this description, then you will probably find this book too difficult at this stage of your preparation. For now, you are better off working on topic-focused material, as found in the All the Quant guide, and ensuring that you have mastered that material before you return to this book.
book 2_p18_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
18
18
general
Try It Yourself Throughout the chapters of this guide, you’ll see Try-It problems— problems designed to test your skills on certain aspects of GMAT problems. Take a look at the following three Try-It problems, which are very difficult. They are at least as hard as any real GMAT problem—probably even harder. Go ahead and...
book 2_p19_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
19
19
coordinate_geometry
Try-It #0-2 Arrow , which is a line segment exactly 5 units long with an arrowhead at A, is constructed in the xy-plane. The x- and y- coordinates of A and B are integers that satisfy the inequalities 0 ≤ x ≤ 9 and 0 ≤ y ≤ 9. How many different arrows with these - properties can be constructed? Try-It #0-3 In the dia...
book 2_p20_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
20
20
general
(Note: This problem does not require any non-GMAT math, such as trigonometry.)
book 2_p21_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
21
21
number_theory
The Purpose of This Book This book is designed to prepare you for the most difficult math problems on the GMAT. So…what is a difficult math problem, from the point of view of the GMAT? A difficult math problem is one that most GMAT test-takers get wrong under exam conditions. In fact, this is essentially how the GMAT meas...
book 2_p22_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
22
22
word_problems
Complex structures Complex structures are essentially disguises for simpler content. These disguises may be difficult to pierce. The path to the answer is twisted or clouded somehow. To solve problems that have simple content but complex structures, you need approaches that are both more general and more creative. This ...
book 2_p23_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
23
23
sequences_patterns
An Illustration Give this problem a whirl. Don’t go on until you have spent a few minutes on it—or until you have figured it out. Try-It #0-4 What should the next number in this sequence be? 1 2 9 64 __ Note: This problem is not exactly GMAT-like, because there is no mathematically definite rule. However, you’ll know w...
book 2_p24_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
24
24
fractions_decimals_percents
You might even say that you need two types of brain. The top-down brain is your conscious self. If you imagine the contents of your head as a big corporation, then your top-down brain is the CEO, responding to input, making decisions, and issuing orders. In cognitive science, the top-down brain is called the executive ...
book 2_p25_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
25
25
sequences_patterns
Each of your brains needs the other one to solve difficult problems. Your top-down brain needs your bottom-up brain to notice patterns, sniff out valuable leads, and make quick, intuitive leaps and connections. But your bottom-up brain is inarticulate and distractible. Only your top- down brain can build plans, pose expl...
book 2_p26_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
26
26
word_problems
You may never have thought explicitly about steps 1 and 2 before. It may have been easy or even automatic for you to Understand easier problems and to Plan your approach to them. As a result, you may tend to dive right into the Solve stage. This is a bad strategy. Mathematicians know that the real math on hard problems...
book 2_p27_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
27
27
number_theory
solved it). The top-down brain is labeled TD; the bottom-up brain is labeled BU. 1 2 9 64 __ TD: “Okay, let’s Understand this thing. At a glance, they’ve given me an increasing list of numbers, and they want me to find the number that “should” go in the blank, whatever “should” means. What’s a good Plan? Hmm. No idea. ...
book 2_p28_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
28
28
sequences_patterns
BU notices no real pattern. There’s 2−3−2 twice as you go across, but so what? And the 1 is weird by itself. 1 2 9 64 __ TD: “No good leads there. Hmm...time to go back to the original and try taking differences.” BU notices no pattern. The numbers look even uglier. 1 2 9 64 __ TD: “Hmm. No good. Go back to original num...
book 2_p29_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
29
29
number_theory
it’s 4 to the third power. That fits.” BU is thrilled: 1, 2, 3, 4 below and 1, 2, 3 up top. 10 21 32 43 __ TD: “Extend le . It’s 10. Confirmed. The bases are 1, 2, 3, 4, etc., and the powers are 0, 1, 2, 3, etc.” BU is content. 10 21 32 43 54 TD: “So the answer is 54, which is 252, or 625.” Your own process was almost ...
book 2_p30_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
30
30
number_theory
factors because they weren’t that useful here? Of course not! A computer can rapidly and easily apply a complicated algorithm with hundreds of steps, but humans can’t. (If you are an engineer or programmer, maybe you wish you could program your own brain, but so far, that’s not possible!) What humans are good at, thoug...
book 2_p31_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
31
31
general
Organize your approach: choose a solution path. Solve Work the problem! You’ll get lots of practice using the UPS process throughout this guide.
book 2_p32_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
32
32
word_problems
Learning How to Think This book is intended to make you smarter. It is also intended to make you scrappier. That description encompasses two main ideas: employing GMAT strategies as well as textbook solution methods and knowing when to let go. If you have traditionally been good at paper-based standardized tests, then ...
book 2_p33_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
33
33
word_problems
GMAT problems o en have back doors—ways to solve that don’t involve crazy computation or genius-level insights. Remember that in theory, GMAT problems can all be solved in two minutes. By searching for the back door, you might avoid all the bear traps that the problem writer set out by the front door! In addition to le...
book 2_p34_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
34
34
word_problems
whether you have the presence of mind to recognize a bad opportunity and the discipline to let it go. Show the GMAT that you know how to manage your scarce resources (time and mental energy) and that you can recognize and cut off a bad opportunity.
book 2_p35_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
35
35
word_problems
Plan of This Book The rest of this book has three parts: Part One: Problem Solving and Data Sufficiency Strategies Chapter 1: Problem Solving: Advanced Principles Chapter 2: Problem Solving: Strategies & Tactics Chapter 3: Data Sufficiency: Principles Chapter 4: Data Sufficiency: Strategies & Tactics Part Two: Strategies ...
book 2_p36_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
36
36
statistics
that apply across several topics but are more specific than the approaches in Part I. Each of the eight chapters in Part I and Part II contains the following: Many of these problems will be GMAT-like in format, but many will not. Part III contains sets of GMAT-like Workout problems, designed to exercise your skills as ...
book 2_p37_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
37
37
general
Solutions to Try-It Problems If you haven’t tried to solve the first three Try-It problems in the Try It Yourself section at the beginning of this chapter, then go back and try them now. Think about how to get your top-down brain and your bottom-up brain to work together like a detective and a bloodhound. Come back whe...
book 2_p38_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
38
38
sets_probability_counting
SOLUTION TO TRY-IT #0-1 … jar is filled with red, white, and blue tokens … chance of randomly selecting … TD: “I need to Understand this problem first. There’s a jar, and it’s got red, white, and blue tokens in it.” BU notices “chance” and “randomly.” That’s probability. TD: “All right, this is a probability problem. N...
book 2_p39_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
39
39
algebra
TD: “Let’s Reflect for a moment to figure out a Plan. How can I approach this? How about algebra— if I name the number of each color, then I can represent each fact and also what I’m looking for. Okay, I use R, W, and B. Make probability fractions. Multiply red and white fractions. Simplify algebraically.” BU is now un...
book 2_p40_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
40
40
algebra
In the very first equation above, each fraction on the le is less than 1, so their product is even smaller. The denominators of the three fractions are all the same. So the numerator of the product (B) must be smaller than either of the other numerators (R and W ). BU notices fractions less than 1. All positive. TD: “...
book 2_p41_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
41
41
sets_probability_counting
Let R = 6 and W = 9. (C) is out too. Try the next possibility.” BU doesn’t like breaking the symmetry between R and W. They seem to be alike. TD: “Does it matter whether R = 6 and W = 9 or the other way around? No, it doesn’t. One is 6, the other is 9. Plug in and go.” TD: “This works. The answer is 3 + 6 + 9 = 18.” T...
book 2_p42_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
42
42
sets_probability_counting
A jar is filled with red, white, and blue tokens … BU is alert—what about 0? TD: “What about 0? Hmm…the wording at the beginning assumes that there actually are tokens of each color. So there can’t be 0 tokens of any kind.” (A) 9 (B) 12 (C) 15 (D) 18 (E) 21 TD: “Now let’s look at the answer choices.” BU notices that th...
book 2_p43_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
43
43
general
Select a white:   , which is not “select a blue” (A) 9 (B) 12 (C) 15 (D) 18 (E) 21 (C) 15 TD: “That doesn’t work either. Knock out (B). Keep going.” BU notices 15 has a few options. Select a red: Select a white: , which is not "select a blue" , which is not "select a blue" (A) 9 (B) 12 (C) 15 (D) 18 (E) 21 (D) 18 , ...
book 2_p44_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
44
44
coordinate_geometry
Many people find this second approach less stressful and more efficient than the textbook approach. In fact, there is no way to find the correct answer by pure algebra. Ultimately, you have to test suitable numbers. Try-It #0-2 Arrow , which is a line segment exactly 5 units long with an arrowhead at A, is constructed...
book 2_p45_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
45
45
number_theory
properties can be constructed? Reread the question.” BU wonders which properties. … exactly 5 units long with an arrowhead at A … the x- and y-coordinates of A and B are to be integers that satisfy the inequalities 0 ≤ x ≤ 9 and 0 ≤ y ≤ 9. TD: “What are the properties of the arrows supposed to be again? Each arrow is 5...
book 2_p46_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
46
46
geometry
There are 10 identical columns: x = 0 through x = 9. 5 × 10 = 50 possible positions for the arrow pointing straight up. 50 × 2 = 100 possible positions for the arrow if it points straight up or to the right. TD: “Great. I’ve Solved one part. Other possibilities?” BU notices the square is the same vertically as horizont...
book 2_p47_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
47
47
geometry
TD: “3−4−5 triangles. Yes. Put the arrow as the hypotenuse of a 3−4−5 triangle. How can this be done? Try to place the arrow. Remember the reversal. Looks like there are four ways if I go 3 up and 4 across: up right, up le , down right, down le .” BU is happy. This is the trick. Four up, three across: TD: “Likewise, t...
book 2_p48_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
48
48
geometry
Try-It #0-3 In the diagram to the right, the value of x is closest to which of the following? SOLUTION TO TRY-IT #0-3 TD: “Okay, let’s Understand this. Redraw the figure. The problem wants the value of x. Now… how about a Plan?” BU notices this is an isosceles triangle, because there are two sides labeled x. How about ...
book 2_p49_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
49
49
geometry
TD: “Hmm...here’s a Plan: add a perpendicular line to make right triangles. Drop the line from the top point. I'll label corners while I'm at it. Now fill in angles.” BU notices 45−45−90 and is happy. TD: “Use the 45−45−90 to write expressions for its sides. Then  can be split up into two pieces, and I can set up the ...
book 2_p50_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
50
50
algebra
BU has no idea how to take the square root of this. TD: “Neither do I. Let’s try estimating. If x2 is about 3.5, then the square root must be a bit less than 2 (since the square root of 4 is 2). 182 is 324 and 192 is 361, so the answer is around 1.8 or 1.9.” TD: “Answer (A) is about 3.5; that matches the squared value,...
book 2_p51_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
51
51
geometry
Alternatively, the question stem asks for an approximate answer, so you can also try estimating from the start. Draw the triangle carefully and start with the same perpendicular line as before. This line is a little shorter than the side of length (which is about 1.4). Call the two shorter legs 1.2 and calculate the ...
book 2_p52_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
52
52
word_problems
PART ONE Problem Solving and Data Sufficiency Strategies In This Part Chapter 1: Problem Solving: Advanced Principles Chapter 2: Problem Solving: Strategies & Tactic Chapter 3: Data Sufficiency: Principles Chapter 4: Data Sufficiency: Strategies & Tactics
book 2_p53_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
53
53
strategy
CHAPTER 1 Problem Solving: Advanced Principles
book 2_p54_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
54
54
strategy
In This Chapter... Principle #1: Understand the Basics Principle #2: Build a Plan Principle #3: Solve—and Put Pen to Paper Principle #4: Review Your Work
book 2_p55_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
55
55
strategy
Chapter 1 Problem Solving: Advanced Principles Chapters 1 and 2 of this book focus on the more fundamental of the two types of GMAT math questions: Problem Solving (PS). Some of the content applies to any kind of math problem, including Data Sufficiency (DS). However, Chapters 3 and 4 deal specifically with DS issues. T...
book 2_p56_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
56
56
word_problems
Principle #1: Understand the Basics Take time to think and plan before you start solving a difficult problem. If Quant is your strength, you may want to dive straight into every problem as soon as you see it, without pausing to consider all of the angles. There are two good reasons to slow down: To remind yourself to sl...
book 2_p57_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
57
57
word_problems
You don’t need to meticulously go through every one of these questions whenever you solve a problem. (However, that’s a good thing to do when you review a problem!) They’re here to help you consider how you might read more productively.  As you read the problem, jot down any given numbers or formulas on your scrap pape...
book 2_p58_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
58
58
number_theory
Try-It #1-1 x = 910 − 317 and is an integer. If n is a positive integer that has exactly two factors, how many different values for n are possible? Glance. This is a PS problem. The answers are numbers but in written form; this format is reserved for problems that ask for the number of numbers or number of possibili...
book 2_p59_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
59
59
number_theory
What do I know? x = 910 − 317 That is, x = a specific large integer, expressed in terms of powers of 9 and 3. is an integer. That is, x is divisible by n, or n is a factor of x. Finally, n is a positive integer that has exactly two factors. Prime numbers have exactly two factors. So I can rephrase the information: n i...
book 2_p61_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
61
61
statistics
Principle #2: Build a Plan Next, think about how you will solve the problem: Reflect. Here are some Pólya questions that help you think about what you know and come up with a plan: Is a good approach already obvious? From your answers above, you may already see a way to reach the answer. If you can envision the rough o...
book 2_p62_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
62
62
number_theory
Organize. For the Try-It #1-1 problem, some of the information is already rephrased (reorganized). Go further now, combining information and simplifying the question: Given: n is a prime number    AND    n is a factor of x. Combined: n is a prime factor of x. Question: How many different values for n are possible? Combi...
book 2_p63_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
63
63
number_theory
Principle #3: Solve—and Put Pen to Paper The third step is to do the work: solve. You’ll want to execute that solution in an error-free way—it would be terrible to get all the thinking correct, then make a careless computational mistake. That’s why we say you should put pen to paper. In the expression 910 − 317, the 3 ...
book 2_p64_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
64
64
sequences_patterns
Think back to those killer Try-It problems in the introduction. Those are not the kinds of problems you can figure out just by looking at them. When you get stuck on a tough problem, take action. Do not just stare, hoping that you suddenly get it. Instead, ask yourself the Pólya questions again and write down whatever ...
book 2_p65_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
65
65
sequences_patterns
Every GMAT Quant problem has a two-minutes-or-faster solution path, which may depend upon a pattern that you’ll need to extrapolate. You’ll know a pattern is needed when a problem asks something that would be impossible to calculate (without a calculator) in two minutes. When this happens, write out the first five to e...
book 2_p66_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
66
66
sequences_patterns
etc. The terms of the sequence are  . . . . Three terms repeat in this cyclical pattern forever; every third term is the same. Note: If you don’t spot a pattern within the first five to eight terms, stop using this approach and see whether there’s another way (including guessing!). The problem asks for the sum, so fin...
book 2_p67_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
67
67
sequences_patterns
The correct answer is (C). It is almost impossible to stare at the recursive definition of this sequence and discern the resulting pattern. The best way to identify the pattern is to calculate a few values of the sequence and look for the pattern. You will learn more about pattern recognition in Chapter 5. 2. DRAW IT O...
book 2_p68_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
68
68
word_problems
Represent Truck A and Truck B as of 1:00 p.m. How does the distance between Truck A and Truck B change as time goes by? Try another point in time. Since the answers are all a matter of minutes a er 1:00 p.m., try a convenient increment of a few minutes. A er 10 minutes, each truck will have traveled 5 miles (30 miles p...
book 2_p69_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
69
69
algebra
Therefore, y could equal 6 or 8 miles. In other words, the trucks will be exactly 10 miles apart at 1:12 p.m. and at 1:16 p.m. Either way, the correct answer is (B). Notice how instrumental these diagrams were for the solution process. You may already accept that Geometry problems require diagrams. However, many other ...
book 2_p70_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
70
70
number_theory
Try-It #1-4 If x and y are positive integers and is the square of an odd integer, what is the smallest possible value of xy ? As you read, jot down the given information. Note that you might not immediately write down the square of an odd integer info if you still have to puzzle out what it means: What does the squar...
book 2_p71_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
71
71
algebra
Are there any patterns or commonalities? All of the numbers are odd. All of the numbers are perfect squares. Therefore, is an odd perfect square. Add that to your notes. The question asks for the smallest possible value of xy. What do you need to figure out in order to find that? If the expression is distracting yo...
book 2_p72_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
72
72
number_theory
In other words, y2 must cancel out all the even factors in 1,620. The y2 must contain at least two 2’s, so y itself has to contain at least one 2. Okay, that takes care of y: at minimum, y must be 2. If so, then the expression becomes . Now, what about x? If you’re not sure, return to your simpler problem thinking. S...
book 2_p73_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
73
73
sequences_patterns
Then, see whether you can adjust the solution to the simpler problem in order to solve the original. To recap, put your work on paper. Don’t try to solve hard problems in your head. Instead, do the following: In general, jot down intermediate results as you go. You may see them in a new light and consider how they fit ...
book 2_p74_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
74
74
word_problems
Principle #4: Review Your Work When you are done with a test or practice set, you are not really done. When you first do a problem under timed conditions, your brain is too busy solving the problem to effectively learn and remember. What you learn from a new problem comes a er you’ve finished it and picked your answer, ...
book 2_p75_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
75
75
general
What could I take from this problem to help me solve other problems in the future?
book 2_p76_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
76
76
sets_probability_counting
When you do the following problem set, apply the first three principles from this chapter to each problem: Understand, Plan, and Solve. Then, review each problem in depth. As you review, do two things: The solutions include our own responses to these two tasks. Yours might look different, and that's fine. Problem Set Id...
book 2_p77_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
77
77
sequences_patterns
(A) (B) (C) (D) (E) 2. If x is a positive integer, what is the units digit of (24)5 + 2x(36)6(17)3 ? 2(A) 3(B) 4(C) 6(D) 8(E) 3. A baker makes a combination of chocolate chip cookies and peanut butter cookies for a school bake sale. His recipes only allow him to make chocolate chip cookies in batches of 7 and peanut ...
book 2_p78_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
78
78
algebra
7(A) 14(B) 21(C) 28(D) 35(E) 4. A rectangular solid is changed such that the width and length are each increased by 1 inch and the height is decreased by 9 inches. Despite these changes, the new rectangular solid has the same volume as the original rectangular solid. If the width and length of the original rectangular ...
book 2_p79_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
79
79
general
−7(A)   7(B)  10(C)  12(D)  14(E)
book 2_p80_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
80
80
number_theory
Solutions Each solution addresses the two steps from the instructions: Identify exactly what the problem is asking for, and what that means in the simplest possible terms. 1) Note at least one general takeaway that might useful on other problems in the future. 2) 1. (C) 1. What it’s asking: The problem is asking for t...
book 2_p81_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
81
81
number_theory
The real question: Plan: 210 to primes → build full list of factors from prime components → distinguish between multiples of 42 and non-multiples → count factors → compute probability. Alternatively, you could list all the factors of 210 using factor pairs. 1 210 2 105 3 70 5 42 6 35 7 30 10 21 14 15
book 2_p82_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
82
82
number_theory
There are 16 factors of 210, and two of them (42 and 210) are multiples of 42. You can also count the factors using 210’s prime factorization: (2)(3)(5) (7) = (21)(31)(51)(71). Here’s a shortcut to determine the number of distinct factors of 210. Add 1 to the power of each prime factor and multiply: There are 16 differe...
book 2_p83_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
83
83
sequences_patterns
the factor-counting shortcut, but only if you do know how to deal with the multiples of 42. 2. (A) 2: 1. What it’s asking: The problem asks for the units digit. Because the problem talks about a product, you care only about the units digits, not the overall values. Furthermore, the problem provides crazy numbers; you a...
book 2_p84_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
84
84
number_theory
3. (E) 35: 1. What it’s asking: The problem asks for the minimum number of chocolate chip cookies. Given: The baker only makes chocolate chip (C) or peanut butter (P) cookies. He can only make chocolate chip cookies in batches of 7 and peanut butter cookies in batches of 6. He makes exactly 95 cookies total. What jumps...
book 2_p85_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
85
85
algebra
7C 6P = 95 − 7C Is 6P a multiple of 6? (i.e., Is P an integer?) 28 67 N 35 60 Y Use the answer choices to calculate the value of 6P. Cross off an answer choice if 6P is not a multiple of 6. The first answer choice that works is the last one. The correct answer is (E). 2. At least one takeaway: The two competing constrai...
book 2_p86_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
86
86
algebra
The width, w, appears in all three constraint equations, so solve for the other variables in terms of w and substitute into the longest constraint: Substitute: Since w can’t be zero, you can divide it out safely. Solve for all variables: The correct answer is (E). At least one takeaway: The question is complex enough t...
book 2_p87_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
87
87
algebra
Notice that, though the initial volume formula seemed long and annoying, the calculations canceled out nicely in the end. This is common on the GMAT—common enough, in fact, to suspect that you may be doing something wrong if the algebra becomes very messy. 5. (D) 12: The question implies that there may be multiple solu...
book 2_p88_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
88
88
algebra
Sum of the different solutions: 5 + 4 + 3 = 12. The correct answer is (D). Approach #2: simplify the equation and use theory to finish it off. Isolate the absolute value: Think it through. You square a number and get the absolute value of that same number (not squared!). Only a few numbers can make that true: 1 squared e...
book 2_p89_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
89
89
word_problems
CHAPTER 2 Problem Solving: Strategies & Tactics
book 2_p90_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
90
90
word_problems
In This Chapter... Advanced Strategies Advanced Guessing Tactics
book 2_p91_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
91
91
word_problems
Chapter 2 Problem Solving: Strategies & Tactics Sometimes you will encounter a Problem Solving (PS) problem that you can’t answer—either because its content is difficult or obscure or because you don’t have enough time to solve completely in two minutes. This chapter describes a series of different methods you might try ...
book 2_p92_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
92
92
strategy
The rest of the chapter is devoted to four specialized tactics that can knock out answer choices or provide clues about how to approach the problem more effectively: One of the most productive strategies on the GMAT is to pick good numbers and plug them into unknowns. Try this when the concepts are especially complex or...
book 2_p93_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
93
93
word_problems
PS Tactic 1: Look for Answer Pairs Some PS questions have answer choices that pair with each other in some way. The correct answer may be part of one of these pairs. PS Tactic 2: Apply Cutoffs Sometimes a back-of-the-envelope estimation can help you eliminate any answer choice above or below a certain cutoff. PS Tactic 3...
book 2_p94_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
94
94
algebra
Advanced Strategies 1. CHOOSE SMART NUMBERS Some types of problems allow you to pick real numbers and solve the problem arithmetically rather than algebraically. For instance, almost any Problem Solving problem that has variables in the answer choices gives you this opportunity. Likewise, you can o en pick a smart numb...
book 2_p95_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
95
95
algebra
Andra, Elif, and Grady each invested in a certain stock. Andra invested q dollars, which was 40% more than Elif invested. If Elif invested 25% less than Grady invested, what was the total amount invested by all three, in terms of q ? This problem can be solved algebraically: write a couple of equations and solve for al...
book 2_p96_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
96
96
strategy
Andra invests 40% more than Elif. For just these two, it would be easier to pick a number for Elif and then calculate Andra’s amount. Elif invests 25% less than Grady. For these two, it is easier to start with Grady and then calculate Elif. As a result, start with Grady, then find Elif, then find Andra. If Grady invest...
book 2_p97_c1
Manhattan Prep GMAT Advanced Quant
book 2.pdf
pdf
97
97
word_problems
have been to figure out Elif’s amount. It is not the case that Elif would be $60, or 40% less than Andra. Rather, Andra is 40% more than Elif: 1.4e = $100, so  . Elif would actually equal approximately $71.42857. Nobody’s going to want to go down that path! At this stage, you have two choices: you can go back and pick...