Last visit was: 21 Jul 2024, 21:54 It is currently 21 Jul 2024, 21:54
Toolkit
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

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.

# Is MNP isosceles? (1) Exactly two of the angles, M and N, have the

SORT BY:
Tags:
Show Tags
Hide Tags
GMAT Tutor
Joined: 27 Oct 2017
Posts: 1895
Own Kudos [?]: 5797 [17]
Given Kudos: 238
WE:General Management (Education)
Manager
Joined: 09 Jun 2018
Posts: 170
Own Kudos [?]: 434 [0]
Given Kudos: 86
Location: United States
GMAT 1: 730 Q50 V39
GPA: 4
WE:Operations (Manufacturing)
Intern
Joined: 23 May 2018
Posts: 35
Own Kudos [?]: 45 [1]
Given Kudos: 27
Location: India
Concentration: Economics, Strategy
Schools: Ivey '22 (A\$)
GMAT 1: 690 Q48 V36
GPA: 4
Manager
Joined: 09 Jun 2018
Posts: 170
Own Kudos [?]: 434 [0]
Given Kudos: 86
Location: United States
GMAT 1: 730 Q50 V39
GPA: 4
WE:Operations (Manufacturing)
Re: Is MNP isosceles? (1) Exactly two of the angles, M and N, have the [#permalink]
shibanis01 wrote:
S1 : Angle M=Angle N => MP=NP
Now, if MP=NP=MN, it's an equilateral triangle.
But, if MP/NP!=MN, it's an isoceles triangle.

Hence, NS.

S2 : Angle N!= Angle P => MN!=MP.
It could be an Isoceles Triangle or an Acute or an Obtuse Triangle.
Hence, NS.

Both S1 & S2 together => SUFFICIENT.
Since 2 sides MP and NP are equal and third side MN is not equal.

Ans = C

Posted from my mobile device

shibanis01 I believe, every equilateral triangle is isosceles, but not every isosceles triangle is equilateral. Here's a link that might help clarify: https://www.sparknotes.com/math/geometr ... /section3/
SVP
Joined: 24 Nov 2016
Posts: 1712
Own Kudos [?]: 1360 [1]
Given Kudos: 607
Location: United States
Re: Is MNP isosceles? (1) Exactly two of the angles, M and N, have the [#permalink]
1
Bookmarks
nkin wrote:
shibanis01 wrote:
S1 : Angle M=Angle N => MP=NP
Now, if MP=NP=MN, it's an equilateral triangle.
But, if MP/NP!=MN, it's an isoceles triangle.

Hence, NS.

S2 : Angle N!= Angle P => MN!=MP.
It could be an Isoceles Triangle or an Acute or an Obtuse Triangle.
Hence, NS.

Both S1 & S2 together => SUFFICIENT.
Since 2 sides MP and NP are equal and third side MN is not equal.

Ans = C

Posted from my mobile device

shibanis01 I believe, every equilateral triangle is isosceles, but not every isosceles triangle is equilateral. Here's a link that might help clarify: https://www.sparknotes.com/math/geometr ... /section3/

(1) Exactly two of the angles, M and N, have the same measure.
"Exactly two" means that the triangle cannot be an equilateral, since ONLY 2 angles can be the same.
GMAT Club Legend
Joined: 12 Sep 2015
Posts: 6804
Own Kudos [?]: 30846 [0]
Given Kudos: 799
Is MNP isosceles? (1) Exactly two of the angles, M and N, have the [#permalink]
Top Contributor
GMATBusters wrote:
Is triangle MNP isosceles?

(1) Exactly two of the angles, M and N, have the same measure.
(2)Angles N and P do not have the same measure.

Target question: Is triangle MNP isosceles?

Statement 1: Exactly two of the angles, M and N, have the same measure.
Perfect. This is the precise definition of an isosceles triangle
The answer to the target question is YES, triangle MNP is isosceles
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: Angles N and P do not have the same measure
Here are two conflicting scenarios that satisfied statement 2
Case a: ∠N = 50°, ∠P = 80°, and ∠M = 50°. In this case, the answer to the target question is YES, triangle MNP is isosceles
Case b: ∠N = 50°, ∠P = 70°, and ∠M = 60°. In this case, the answer to the target question is NO, triangle MNP is not isosceles
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Cheers,
Brent­
Director
Joined: 07 Jan 2022
Posts: 586
Own Kudos [?]: 451 [0]
Given Kudos: 725
Schools: NUS '25 (A)
GMAT 1: 740 Q51 V38
GPA: 4
Is MNP isosceles? (1) Exactly two of the angles, M and N, have the [#permalink]
GMATBusters wrote:
Is triangle MNP isosceles?

(1) Exactly two of the angles, M and N, have the same measure.

(2)Angles N and P do not have the same measure.

(1) Exactly two angles have the same measure. Sufficient.

(2) Two angles not having the same measure gives us no information about the third angle. Insufficient.

Hence, A.­
Non-Human User
Joined: 09 Sep 2013
Posts: 34041
Own Kudos [?]: 853 [0]
Given Kudos: 0
Re: Is MNP isosceles? (1) Exactly two of the angles, M and N, have the [#permalink]
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Re: Is MNP isosceles? (1) Exactly two of the angles, M and N, have the [#permalink]
Moderator:
Math Expert
94441 posts