Events & Promotions
|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
May 1408:30 AM PDT
-09:30 AM PDT
Most GMAT test-takers are intimidated by the hardest GMAT Verbal questions. In this session, Target Test Prep GMAT instructor Erika Tyler-John, a 100th percentile GMAT scorer, will show you how top scorers break down challenging Verbal questions..
May 1212:00 PM EDT
-11:59 PM EDT
Make the most of your break with the most realistic GMAT™ prep. Take up to $700 off select products.- May 13
08:30 AM PDT
-09:30 AM PDT
In Episode 4 of our GMAT Ninja CR series, we tackle the most intimidating CR question type: Boldface & "Legalese" questions. If you've ever stared at an answer choice that reads, "The first is a consideration introduced to counter a position that... - Jun 10
06:00 AM PDT
-06:15 PM PDT
Register for the GMAT Club Virtual MBA Spotlight Fair – the world’s premier event for serious MBA candidates. This is your chance to hear directly from Admissions Directors at nearly every Top 30 MBA program..
Updated on: 27 Sep 2021, 02:36
Originally posted by MathRevolution on 25 Apr 2019, 01:21.
Last edited by MathRevolution on 27 Sep 2021, 02:36, edited 1 time in total.
Last edited by MathRevolution on 27 Sep 2021, 02:36, edited 1 time in total.
Kudos
Bookmarks
MathRevolution
=>
Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution.
The first step of the VA (Variable Approach) method is to modify the original condition and the question. We then recheck the question.
Since we have \(1\) variable (\(n\)) and \(0\) equations, D is most likely to be the answer. So, we should consider each condition on its own first.
Condition 1)
Only \(n =2\) makes \(n(n-1)\) a prime number.
Thus, condition 1) is sufficient.
Condition 2)
Integers with four factors have the form \(p*q\) or \(p^3\), where \(p\) and \(q\) are prime integers.
It is impossible to have \(n(n+1)=p^3\), where \(n\) is an integer and \(p\) is a prime number.
The only time \(n(n+1) = pq\) is when \(n(n+1) = 2*3\) and \(n =2\).
Condition 2) is sufficient since it yields a unique solution.
Therefore, D is the answer.
Answer: D
If the original condition includes “1 variable”, or “2 variables and 1 equation”, or “3 variables and 2 equations” etc., one more equation is required to answer the question. If each of conditions 1) and 2) provide an additional equation, there is a 59% chance that D is the answer, a 38% chance that A or B is the answer, and a 3% chance that the answer is C or E. Thus, answer D (conditions 1) and 2), when applied separately, are sufficient to answer the question) is most likely, but there may be cases where the answer is A,B,C or E.
25 Apr 2019, 01:22
Kudos
Bookmarks
[GMAT math practice question]
(inequality) If \(x, y\) and \(z\) are integers with \(x<y<z\), is \(z>4\)?
\(1) x+y+z=12\)
\(2) x<4\)
(inequality) If \(x, y\) and \(z\) are integers with \(x<y<z\), is \(z>4\)?
\(1) x+y+z=12\)
\(2) x<4\)
Updated on: 27 Sep 2021, 02:36
Originally posted by MathRevolution on 26 Apr 2019, 06:48.
Last edited by MathRevolution on 27 Sep 2021, 02:36, edited 1 time in total.
Last edited by MathRevolution on 27 Sep 2021, 02:36, edited 1 time in total.
Kudos
Bookmarks
MathRevolution
=>
Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution.
Since we have \(2\) variables (\(x\) and \(y\)) and \(0\) equations, C is most likely to be the answer. So, we should consider conditions 1) & 2) together first. After comparing the number of variables and the number of equations, we can save time by considering conditions 1) & 2) together first.
Conditions 1) & 2)
If \(m = 9\) and \(n = 3\), then \(mn = 9^3 = (3^2)^3 = 3^6 = (3^3)^2 = 27^2,\) which is a perfect square, and the answer is ‘yes’.
If \(m = 3\) and \(n = 3\), then \(mn = 3^3 = (3)^3 = 27\), which is not a perfect square, and the answer is ‘no’.
Both conditions together are not sufficient, since they don’t yield a unique answer.
Therefore, E is the answer.
Answer: E
In cases where 3 or more additional equations are required, such as for original conditions with “3 variables”, or “4 variables and 1 equation”, or “5 variables and 2 equations”, conditions 1) and 2) usually supply only one additional equation. Therefore, there is an 80% chance that E is the answer, a 15% chance that C is the answer, and a 5% chance that the answer is A, B or D. Since E (i.e. conditions 1) & 2) are NOT sufficient, when taken together) is most likely to be the answer, it is generally most efficient to begin by checking the sufficiency of conditions 1) and 2), when taken together. Obviously, there may be occasions on which the answer is A, B, C or D.
