"If n is a positive integer, is n equal to 100?
(1) (sqrt)n > 9
(2) (sqrt)n < 11 "
According to the first statement n could be 100 or 121 or 144 or 169 and so on. So it's insufficient.
Statement 2 is also insufficient since n could 100 or 81 or 64 or 49 etc...
But if we combine them the result is n=100. So it should be C.
What is the O.A?
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
(sqrt)n
This topic has expert replies
-
GMATGuruNY
- GMAT Instructor
- Posts: 15539
- Joined: Tue May 25, 2010 12:04 pm
- Location: New York, NY
- Thanked: 13060 times
- Followed by:1906 members
- GMAT Score:790
Statement 1: √n > 9Malolo355 wrote:"If n is a positive integer, is n equal to 100?
(1) (sqrt)n > 9
(2) (sqrt)n < 11 "
According to the first statement n could be 100 or 121 or 144 or 169 and so on. So it's insufficient.
Statement 2 is also insufficient since n could 100 or 81 or 64 or 49 etc...
But if we combine them the result is n=100. So it should be C.
What is the O.A?
Squaring both sides, we get:
n > 81.
Since n can be ANY INTEGER greater than 81, INSUFFICIENT.
Statement 2: √n < 11
Squaring both sides, we get:
n < 121.
Since n can be ANY POSITIVE INTEGER less than 121, INSUFFICIENT.
Statements combined:
Since n can be ANY INTEGER between 81 and 121, INSUFFICIENT.
The correct answer is E.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
-
GMATGuruNY
- GMAT Instructor
- Posts: 15539
- Joined: Tue May 25, 2010 12:04 pm
- Location: New York, NY
- Thanked: 13060 times
- Followed by:1906 members
- GMAT Score:790
While the value of n itself must be an integer, nothing in the problem requires that √n be an integer.Malolo355 wrote:So in other words you claim that (sqrt)n could be a non-integer ?
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
GMAT/MBA Expert
-
[email protected]
- Elite Legendary Member
- Posts: 10392
- Joined: Sun Jun 23, 2013 6:38 pm
- Location: Palo Alto, CA
- Thanked: 2867 times
- Followed by:511 members
- GMAT Score:800
Hi Malolo355,
DS Questions are built to test a number of traits: organization, thoroughness, accuracy, attention-to-detail, etc.
Occasionally, you'll have to consider non-integers (fractions, decimals, etc.) when dealing with a DS question (and even some PS questions require a focus on non-integers). It doesn't happen very often, but if your goal is to score at a high level in the Quant, you have to be prepared to do a bit more work and think about more possibilities than just integers.
GMAT assassins aren't born, they're made,
Rich
DS Questions are built to test a number of traits: organization, thoroughness, accuracy, attention-to-detail, etc.
Occasionally, you'll have to consider non-integers (fractions, decimals, etc.) when dealing with a DS question (and even some PS questions require a focus on non-integers). It doesn't happen very often, but if your goal is to score at a high level in the Quant, you have to be prepared to do a bit more work and think about more possibilities than just integers.
GMAT assassins aren't born, they're made,
Rich
