GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 18 Nov 2018, 04:20

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
Events & Promotions in November
PrevNext
SuMoTuWeThFrSa
28293031123
45678910
11121314151617
18192021222324
2526272829301
Open Detailed Calendar
  • How to QUICKLY Solve GMAT Questions - GMAT Club Chat

     November 20, 2018

     November 20, 2018

     09:00 AM PST

     10:00 AM PST

    The reward for signing up with the registration form and attending the chat is: 6 free examPAL quizzes to practice your new skills after the chat.
  • The winning strategy for 700+ on the GMAT

     November 20, 2018

     November 20, 2018

     06:00 PM EST

     07:00 PM EST

    What people who reach the high 700's do differently? We're going to share insights, tips and strategies from data we collected on over 50,000 students who used examPAL.

In △ABC, is any angle greater than 90°?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Manager
Manager
avatar
S
Joined: 11 Mar 2018
Posts: 87
In △ABC, is any angle greater than 90°?  [#permalink]

Show Tags

New post Updated on: 22 Oct 2018, 06:59
2
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

51% (01:06) correct 49% (01:28) wrong based on 59 sessions

HideShow timer Statistics

In △ABC, is any angle greater than 90°?

(1) AB = 2, BC = 8, AC = 9
(2) Sum of the greatest and the second greatest angle is 160°

_________________

Regards
AD
---------------------------------
A Kudos is one more question and its answer understood by somebody !!!


Originally posted by adstudy on 17 Jul 2018, 23:06.
Last edited by gmatbusters on 22 Oct 2018, 06:59, edited 1 time in total.
Edited the Question
DS Forum Moderator
avatar
P
Joined: 21 Aug 2013
Posts: 1369
Location: India
Premium Member
Re: In △ABC, is any angle greater than 90°?  [#permalink]

Show Tags

New post 17 Jul 2018, 23:15
2
2
adstudy wrote:
In △ABC, is any angle greater than 90°?

(1) AB = 1, BC = 8, AC = 9
(2) Sum of the greatest and the second greatest angle is 160°


If we have the lengths of sides of a triangle, then to determine whether the triangle is acute (all angles less than 90) or right angled (one angle = 90) or obtuse (one angle > 90); we should square all the three lengths of sides.
If square of longest side is smaller than the sum of squares of two smaller sides, its an acute angled triangle
If square of longest side is equal to the sum of squares of two smaller sides, its a right angled triangle
If square of longest side is greater than the sum of squares of two smaller sides, its an obtuse angled triangle

(1) As the lengths are given, we can square and determine the answer. Sufficient (Its obtuse by the way, so one angle will be > 90).

(2) If sum of two angles = 160, both could be less than 90 (80, 80) or one could be greater than 90 (100, 60). Not sufficient.

Hence A answer
Senior DS Moderator
User avatar
D
Joined: 27 Oct 2017
Posts: 1029
Location: India
Concentration: International Business, General Management
GPA: 3.64
WE: Business Development (Energy and Utilities)
Premium Member CAT Tests
Re: In △ABC, is any angle greater than 90°?  [#permalink]

Show Tags

New post 17 Jul 2018, 23:41
1) As length of all three sides are given, a unique triangle can be constructed and hence angles can be determined.
SUFFICIENT.

2) sum of largest and second largest angle = 160.
Now the 2 angles can be 100, 60 or 80,80.
Hence NOT SUFFICIENT.

Answer A

Posted from my mobile device
_________________

Win GMAT CLUB Test- Weekly Quant Quiz Contest
Weekly Quant Quiz Questions- Direct Download
SC: Confusable words

All you need for Quant, GMAT PS Question Directory,GMAT DS Question Directory
Error log/Key Concepts
Combination Concept: Division into groups
Question of the Day (QOTD)
Free GMAT CATS

Intern
Intern
avatar
B
Joined: 18 Feb 2018
Posts: 1
Re: In △ABC, is any angle greater than 90°?  [#permalink]

Show Tags

New post 22 Oct 2018, 06:43
2
I think the answer is E since "Given a triangle ABC, the sum of the lengths of any two sides of the triangle is greater than the length of the third side". In this way, in statement (1), AB+BC=1+8=9=AC, thus such triangle does not exist. In this way, statement (1) is wrong as well.

amanvermagmat wrote:
adstudy wrote:
In △ABC, is any angle greater than 90°?

(1) AB = 1, BC = 8, AC = 9
(2) Sum of the greatest and the second greatest angle is 160°


If we have the lengths of sides of a triangle, then to determine whether the triangle is acute (all angles less than 90) or right angled (one angle = 90) or obtuse (one angle > 90); we should square all the three lengths of sides.
If square of longest side is smaller than the sum of squares of two smaller sides, its an acute angled triangle
If square of longest side is equal to the sum of squares of two smaller sides, its a right angled triangle
If square of longest side is greater than the sum of squares of two smaller sides, its an obtuse angled triangle

(1) As the lengths are given, we can square and determine the answer. Sufficient (Its obtuse by the way, so one angle will be > 90).

(2) If sum of two angles = 160, both could be less than 90 (80, 80) or one could be greater than 90 (100, 60). Not sufficient.

Hence A answer
Senior DS Moderator
User avatar
D
Joined: 27 Oct 2017
Posts: 1029
Location: India
Concentration: International Business, General Management
GPA: 3.64
WE: Business Development (Energy and Utilities)
Premium Member CAT Tests
Re: In △ABC, is any angle greater than 90°?  [#permalink]

Show Tags

New post 22 Oct 2018, 07:02
Hi
There was a typo in the statement 1, It is revised now.
Thanks for reporting.

kaylajiang wrote:
I think the answer is E since "Given a triangle ABC, the sum of the lengths of any two sides of the triangle is greater than the length of the third side". In this way, in statement (1), AB+BC=1+8=9=AC, thus such triangle does not exist. In this way, statement (1) is wrong as well.

amanvermagmat wrote:
adstudy wrote:
In △ABC, is any angle greater than 90°?

(1) AB = 2, BC = 8, AC = 9
(2) Sum of the greatest and the second greatest angle is 160°


If we have the lengths of sides of a triangle, then to determine whether the triangle is acute (all angles less than 90) or right angled (one angle = 90) or obtuse (one angle > 90); we should square all the three lengths of sides.
If square of longest side is smaller than the sum of squares of two smaller sides, its an acute angled triangle
If square of longest side is equal to the sum of squares of two smaller sides, its a right angled triangle
If square of longest side is greater than the sum of squares of two smaller sides, its an obtuse angled triangle

(1) As the lengths are given, we can square and determine the answer. Sufficient (Its obtuse by the way, so one angle will be > 90).

(2) If sum of two angles = 160, both could be less than 90 (80, 80) or one could be greater than 90 (100, 60). Not sufficient.

Hence A answer

_________________

Win GMAT CLUB Test- Weekly Quant Quiz Contest
Weekly Quant Quiz Questions- Direct Download
SC: Confusable words

All you need for Quant, GMAT PS Question Directory,GMAT DS Question Directory
Error log/Key Concepts
Combination Concept: Division into groups
Question of the Day (QOTD)
Free GMAT CATS

GMATH Teacher
User avatar
G
Status: GMATH founder
Joined: 12 Oct 2010
Posts: 477
In △ABC, is any angle greater than 90°?  [#permalink]

Show Tags

New post 22 Oct 2018, 11:28
amanvermagmat wrote:
adstudy wrote:
In △ABC, is any angle greater than 90°?

(1) AB = 2, BC = 8, AC = 9
(2) Sum of the greatest and the second greatest angle is 160°


If we have the lengths of sides of a triangle, then to determine whether the triangle is acute (all angles less than 90) or right angled (one angle = 90) or obtuse (one angle > 90); we should square all the three lengths of sides.
If square of longest side is smaller than the sum of squares of two smaller sides, its an acute angled triangle
If square of longest side is equal to the sum of squares of two smaller sides, its a right angled triangle
If square of longest side is greater than the sum of squares of two smaller sides, its an obtuse angled triangle

(1) As the lengths are given, we can square and determine the answer. Sufficient (Its obtuse by the way, so one angle will be > 90).

(2) If sum of two angles = 160, both could be less than 90 (80, 80) or one could be greater than 90 (100, 60). Not sufficient.

Hence A answer


Hi amanvermagmat ,

Congrats (and kudos)!

Your solution (with very well-written details included) was really a pleasure to read!

Important (for all readers): we must consider 2 in the place of 1, as I have shown in bold red. Otherwise the triangle does not exist!
(This detail was correctly pointed out by kaylajiang . Kudos, too!)

Regards,
Fabio.
_________________

Fabio Skilnik :: https://GMATH.net (Math for the GMAT) or GMATH.com.br (Portuguese version)
Course release PROMO : finish our test drive till 30/Nov with (at least) 50 correct answers out of 92 (12-questions Mock included) to gain a 50% discount!

GMAT Club Bot
In △ABC, is any angle greater than 90°? &nbs [#permalink] 22 Oct 2018, 11:28
Display posts from previous: Sort by

In △ABC, is any angle greater than 90°?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.