Last visit was: 19 Nov 2025, 17:07 It is currently 19 Nov 2025, 17:07
Close
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

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,390
Own Kudos:
Given Kudos: 99,977
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,390
Kudos: 778,370
 [89]
7
Kudos
Add Kudos
81
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,390
Own Kudos:
Given Kudos: 99,977
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,390
Kudos: 778,370
 [21]
15
Kudos
Add Kudos
6
Bookmarks
Bookmark this Post
User avatar
Jackal
Joined: 21 Feb 2012
Last visit: 08 Apr 2016
Posts: 50
Own Kudos:
131
 [7]
Given Kudos: 63
Posts: 50
Kudos: 131
 [7]
7
Kudos
Add Kudos
Bookmarks
Bookmark this Post
General Discussion
avatar
akhilshrmaa
Joined: 12 May 2014
Last visit: 14 Jan 2016
Posts: 12
Own Kudos:
46
 [32]
Given Kudos: 4
Location: United States
Concentration: Strategy, Operations
Schools: IIMC'17
GMAT Date: 10-22-2014
GPA: 1.9
WE:Engineering (Energy)
Schools: IIMC'17
Posts: 12
Kudos: 46
 [32]
32
Kudos
Add Kudos
Bookmarks
Bookmark this Post
According to the question the maximum value of either x^2 or y^2 can be 100, which implies that the greatest absolute value of either x or y can be 10

option C indicates that absolute value of x is greater than 10 which cannot be the case.

kudos..:)
User avatar
plaverbach
User avatar
Retired Moderator
Joined: 25 Mar 2014
Last visit: 28 Sep 2021
Posts: 215
Own Kudos:
535
 [3]
Given Kudos: 250
Status:Studying for the GMAT
Location: Brazil
Concentration: Technology, General Management
GMAT 1: 700 Q47 V40
GMAT 2: 740 Q49 V41 (Online)
WE:Business Development (Finance: Venture Capital)
Products:
GMAT 2: 740 Q49 V41 (Online)
Posts: 215
Kudos: 535
 [3]
3
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Can this be solved visually??
1) as a circle on the xy plane
OR
2) as a tringle(pitagoras)
avatar
praveen8047
Joined: 30 May 2013
Last visit: 08 Feb 2020
Posts: 21
Own Kudos:
75
 [5]
Given Kudos: 10
GMAT 1: 600 Q50 V21
GMAT 2: 640 Q49 V29
Products:
GMAT 2: 640 Q49 V29
Posts: 21
Kudos: 75
 [5]
4
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
I started with values of x & y as :
10 & 0, this rejects options (a) & (b)
5√2 & 5√2, this reject option (d)

For (c) & (e), if we take another look at the given statement, it can be consider an equation of right angle triangle.
x² + y² = 10²
And we know that sum of two sides is always greater than the third side.
Hence |x| > |y| + 10 can never be true.
avatar
JIAA
Joined: 18 Jul 2018
Last visit: 09 Nov 2020
Posts: 23
Own Kudos:
11
 [1]
Given Kudos: 63
Location: United Arab Emirates
Posts: 23
Kudos: 11
 [1]
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Bunuel
Official Solution:

\(x^2 + y^2 = 100\). All of the following could be true EXCEPT

A. \(|x| + |y| = 10\)
B. \(|x| \gt |y|\)
C. \(|x| \gt |y| + 10\)
D. \(|x| = |y|\)
E. \(|x| - |y| = 5\)


A. \(|x| + |y| = 10\) is possible if one is 0 and the other is 10.

B. \(|x| \gt |y|\) is possible if \(|x| \gt |5\sqrt{2}|\) and \(|y| \lt |5\sqrt{2}|\)

C. \(|x| \gt |y| + 10\) is never possible because if \(|x| \gt 10\), \(x^2+y^2\) becomes greater than 100, which is wrong.

D. \(|x| = |y|\) is possible if each is equal to \(|5\sqrt{2}|\).

E. \(|x| - |y| = 5\) is possible if \(|x| = |9.11|\) and \(|y| = |4.11|\).

Therefore all but C are possible. \(|x| \gt |y| + 10\) means \(x\) is greater than 10, which is not possible.


Answer: C



Xylan can you help?? What if i don't want to do number plugging??
User avatar
XyLan
User avatar
ESMT Berlin School Moderator
Joined: 16 Jun 2018
Last visit: 18 Nov 2025
Posts: 245
Own Kudos:
483
 [3]
Given Kudos: 104
Status:The darker the night, the nearer the dawn!
Concentration: Strategy, Technology
GMAT 1: 640 Q50 V25
GMAT 2: 680 Q50 V32
Products:
GMAT 2: 680 Q50 V32
Posts: 245
Kudos: 483
 [3]
3
Kudos
Add Kudos
Bookmarks
Bookmark this Post
JIAA
Bunuel
Official Solution:

\(x^2 + y^2 = 100\). All of the following could be true EXCEPT

A. \(|x| + |y| = 10\)
B. \(|x| \gt |y|\)
C. \(|x| \gt |y| + 10\)
D. \(|x| = |y|\)
E. \(|x| - |y| = 5\)


A. \(|x| + |y| = 10\) is possible if one is 0 and the other is 10.

B. \(|x| \gt |y|\) is possible if \(|x| \gt |5\sqrt{2}|\) and \(|y| \lt |5\sqrt{2}|\)

C. \(|x| \gt |y| + 10\) is never possible because if \(|x| \gt 10\), \(x^2+y^2\) becomes greater than 100, which is wrong.

D. \(|x| = |y|\) is possible if each is equal to \(|5\sqrt{2}|\).

E. \(|x| - |y| = 5\) is possible if \(|x| = |9.11|\) and \(|y| = |4.11|\).

Therefore all but C are possible. \(|x| \gt |y| + 10\) means \(x\) is greater than 10, which is not possible.


Answer: C



Xylan can you help?? What if i don't want to do number plugging??

JIAA It's completely okay if you do NOT want to do number plugging.
However, aspire to reach the CORRECT solution in the least possible time so that one can spend judicious time on 700+ Qs.

Quote:
Remember, Our arsenal should be equipped with all sorts of ammunition to tame the beast such as Reverse-solving, plugging different numbers, edge-case scenarios, etc.

The equation \(x^2 + y^2 = 100\) is actually the locus of a circle with the origin as the center and radius of 10 units.
Before you move to answer-choice-analysis:
    If possible Pre-Think the problem such as the allowable value of X and Y -
    According to the question, the maximum value of either \(x^2\) or \(y^2\) can be 100, which implies that the greatest absolute value of either X or Y can be 10.
    Thus, \(|x|\) must be \(<= 10\). Refer the attached picture.

Hence, \(|x|\) CANNOT be \(> 10\). Let alone \(|x|\) being greater than \(|y| + 10\).

If we take another look at the given statement \(x^2 + y^2 = 100\), it can be considered an equation of right angle triangle with hypotenuse = 10 and perpendicular-sides as X and Y.
    \(x^2 + y^2 = 100\)
    And we know that the sum of two sides is always greater than the third side.
    Thus: |y| + 10 > |x| : The third-side is smaller than the sum of other two-sides.
    Therefore, OptionC is incorrect as it says \(|x| > |y| + 10\), which can NEVER be true.

Attachments

File comment: Equation of the given circle with centre at (0,0) and radius = 10.
Equation of a circle.PNG
Equation of a circle.PNG [ 52.67 KiB | Viewed 15865 times ]

User avatar
Will2020
User avatar
Current Student
Joined: 24 Jan 2017
Last visit: 04 Mar 2022
Posts: 135
Own Kudos:
51
 [1]
Given Kudos: 1,120
Location: Brazil
Concentration: Entrepreneurship, Strategy
GPA: 3.2
WE:Consulting (Healthcare/Pharmaceuticals)
Products:
Posts: 135
Kudos: 51
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel XyLan I don't understand the explanation for E, can you help? Tks! :)
User avatar
XyLan
User avatar
ESMT Berlin School Moderator
Joined: 16 Jun 2018
Last visit: 18 Nov 2025
Posts: 245
Own Kudos:
483
 [1]
Given Kudos: 104
Status:The darker the night, the nearer the dawn!
Concentration: Strategy, Technology
GMAT 1: 640 Q50 V25
GMAT 2: 680 Q50 V32
Products:
GMAT 2: 680 Q50 V32
Posts: 245
Kudos: 483
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Will2020


Bunuel XyLan I don't understand the explanation for E, can you help? Tks! :)
Will2020, You can VERIFY ( do NOT solve ) this option-E using quadratic:
    \(x^2 + y^2 = 100 \)
    OR
    \(x^2 = 100 - y^2\) ------------------(1)

    In Option-E, \(|x| - |y| = 5\\
    -------> |x| = 5 + |y|\)
    Squaring both sides:
      \(x^2 = 25 + 10y + y^2 \) ---------------(2)

    Equating \(x^2\) from (1) & (2)
    \(25 + 10y + y^2 = 100 - y^2\)
    \(2*y^2 + 10y - 75 = 0\)

We have fetched a quadratic equation whose solution would give get 2 values of Y -------And, then respective values of ----> X

Now, here comes the catch
    You do NOT need to solve this ENTIRE equation to reach the answer.
    Be as EFFICIENT as possible: We for SURE know it's possible: Option-E could be true based on the values of X and Y.

    Mark and Move!

Learning -
    GMAT is NOT about reaching the perfect answer, but it's about reaching the answer in the least amount of time.

Keep me posted if you have any queries! :)

PS: Exact values are:
    \(x=(5/2)*(\sqrt{7}+1)\),
    \(y=(5/2)*(\sqrt{7}−1)\)
User avatar
XyLan
User avatar
ESMT Berlin School Moderator
Joined: 16 Jun 2018
Last visit: 18 Nov 2025
Posts: 245
Own Kudos:
483
 [1]
Given Kudos: 104
Status:The darker the night, the nearer the dawn!
Concentration: Strategy, Technology
GMAT 1: 640 Q50 V25
GMAT 2: 680 Q50 V32
Products:
GMAT 2: 680 Q50 V32
Posts: 245
Kudos: 483
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
800GMAT2019
Why is answer C incorrect?

X=√96.
Y=2

(√96 X √96) + 2^2 = 100

I am misusing square root here? It seems that C is possible...

--

x2+y2=100x2+y2=100 . All of the following could be true EXCEPT

A. |x|+|y|=10
B. |x|>|y|
C. |x|>|y|+10 ...this can be true?
D. |x|=|y|
E. |x|−|y|=5
800GMAT2019,
Let's play with the numbers that you have chosen:
    X=√96 = 9.797.
    Y=2

    Simplifying further:
      \(|x| = 9.797\)
      \(|y| = 2\)

In Option-C, \(|x| > |y|+10\)
    RHS ( Right-Hand-Side ) of inequality: |y|+10 = 2 + 10 = 12

    LHS ( Left-Hand-Side ) of inequality: |x| = 9.79

\(9.79 < 12\)
LHS is for sure < RHS.

Thus, Option-C is NOT possible. Hence, the correct answer.

Keep me posted if you have any queries! :)
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,390
Own Kudos:
Given Kudos: 99,977
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,390
Kudos: 778,370
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I have edited the question and the solution by adding more details to enhance its clarity. I hope it is now easier to understand.
User avatar
BottomJee
User avatar
Retired Moderator
Joined: 05 May 2019
Last visit: 09 Jun 2025
Posts: 996
Own Kudos:
Given Kudos: 1,009
Affiliations: GMAT Club
Location: India
GMAT Focus 1: 645 Q82 V81 DI82
GMAT 1: 430 Q31 V19
GMAT 2: 570 Q44 V25
GMAT 3: 660 Q48 V33
GPA: 3.26
WE:Engineering (Manufacturing)
Products:
GMAT Focus 1: 645 Q82 V81 DI82
GMAT 3: 660 Q48 V33
Posts: 996
Kudos: 1,327
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I think this is a high-quality question and I agree with explanation.
User avatar
Rance14
Joined: 24 May 2023
Last visit: 26 Oct 2024
Posts: 49
Own Kudos:
36
 [1]
Given Kudos: 205
Location: India
Posts: 49
Kudos: 36
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Is there a way to solve this question without using coordinate geometry?
User avatar
KarishmaB
Joined: 16 Oct 2010
Last visit: 19 Nov 2025
Posts: 16,267
Own Kudos:
77,001
 [2]
Given Kudos: 482
Location: Pune, India
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 16,267
Kudos: 77,001
 [2]
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Bunuel
If \(x^2 + y^2 = 100\), all of the following could be true EXCEPT:


A. \(|x| + |y| = 10\)
B. \(|x| \gt |y|\)
C. \(|x| \gt |y| + 10\)
D. \(|x| = |y|\)
E. \(|x| - |y| = 5\)

\(x^2 + y^2 = 100\)

\(|x|^2 + |y|^2 = 100\)

100 is the sum of two non-negative terms. This means each term (x^2 or y^2) can be 100 at the most (in which case the other term will be 0).
Then the maximum value of |x| or |y| is 10.

Various values of |x| and |y| are possible:

\(|x| =10, |y| = 0\)
\(|x| = 9, |y| = \sqrt{19}\)
...
\(|x| = \sqrt{50}, |y| = \sqrt{50}\)
...
\(|x| = \sqrt{19}, |y| = 9\)
\(|x| =0, |y| = 10\)

But neither |x| nor |y| can be greater than 10.
Hence \(|x| \gt |y| + 10\) is not possible. All others are possible.

Answer (C)
User avatar
Manvi01
Joined: 09 Jul 2024
Last visit: 25 May 2025
Posts: 11
Given Kudos: 225
Location: India
Posts: 11
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I like the solution - it’s helpful.
User avatar
miag
Joined: 10 Dec 2023
Last visit: 18 Nov 2025
Posts: 189
Own Kudos:
Given Kudos: 143
Location: India
Concentration: Marketing, Sustainability
GMAT Focus 1: 675 Q87 V83 DI80
Products:
Expert
Expert reply
GMAT Focus 1: 675 Q87 V83 DI80
Posts: 189
Kudos: 73
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I did not quite understand the solution. didnt understand the explanation of option E)
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,390
Own Kudos:
Given Kudos: 99,977
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,390
Kudos: 778,370
Kudos
Add Kudos
Bookmarks
Bookmark this Post
miag
I did not quite understand the solution. didnt understand the explanation of option E)

On the circle x^2 + y^2 = 100, (10, 0) gives |x| - |y| = 10. As you move along the circle, |x| drops and |y| rises smoothly. So |x| - |y| = 5 must happen somewhere. That’s why E is possible.

Please review the discussion above for alternative solutions.

Hope it helps.
User avatar
Amrinder12
Joined: 16 Nov 2024
Last visit: 22 Oct 2025
Posts: 4
Given Kudos: 1
Posts: 4
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Is this relevant for GMAT focus? If not can you please update question bank. I do not want to practice questions that are not required. This test is hard enough already.
User avatar
hr1212
User avatar
GMAT Forum Director
Joined: 18 Apr 2019
Last visit: 17 Nov 2025
Posts: 621
Own Kudos:
Given Kudos: 1,483
GMAT Focus 1: 775 Q90 V85 DI90
Products:
Expert
Expert reply
GMAT Focus 1: 775 Q90 V85 DI90
Posts: 621
Kudos: 925
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I think this question is pretty relevant. The key is to select numbers that quickly eliminate incorrect options. All you need is one good example to rapidly narrow down your choices -

A. \(|x| + |y| = 10\) => x=10 & y=0
B. \(|x| \gt |y|\) => x=10 & y=0
C. \(|x| \gt |y| + 10\) => x & y can take max value of 10, because in that case other variable would be 0. And if we have, y=0.01, then x=10.01 as per this equation, which is not possible, hence this is incorrect.
D. \(|x| = |y|\) => x=sqrt(50) & y=sqrt(50)
E. \(|x| - |y| = 5\) => This could seem a bit tricky to eliminate directly but one way here could be to square this => x^2 + y^2 - 2|x||y| = 25 => 2|x||y| = 75. So there does exist some value of x & y satisfying this equation.

IMO: C

If you can't figure out direct ways, figure out smart ways to quickly walk through options.
Amrinder12
Is this relevant for GMAT focus? If not can you please update question bank. I do not want to practice questions that are not required. This test is hard enough already.
Moderators:
Math Expert
105390 posts
Founder
42387 posts