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

It is currently 13 Nov 2018, 08:54

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
  • Essential GMAT Time-Management Hacks

     November 14, 2018

     November 14, 2018

     07:00 PM PST

     08:00 PM PST

    Join the webinar and learn time-management tactics that will guarantee you answer all questions, in all sections, on time. Save your spot today! Nov. 14th at 7 PM PST
  • $450 Tuition Credit & Official CAT Packs FREE

     November 15, 2018

     November 15, 2018

     10:00 PM MST

     11:00 PM MST

    EMPOWERgmat is giving away the complete Official GMAT Exam Pack collection worth $100 with the 3 Month Pack ($299)

Please refer to the figure above, triangle ABC is an isosceles triang

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

Hide Tags

Senior DS Moderator
User avatar
D
Joined: 27 Oct 2017
Posts: 1067
Location: India
Concentration: International Business, General Management
GPA: 3.64
WE: Business Development (Energy and Utilities)
Premium Member CAT Tests
Please refer to the figure above, triangle ABC is an isosceles triang  [#permalink]

Show Tags

New post 03 Nov 2018, 09:05
1
4
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

35% (02:10) correct 65% (02:14) wrong based on 18 sessions

HideShow timer Statistics

Attachment:
5.jpg
5.jpg [ 9.71 KiB | Viewed 342 times ]

Please refer to the figure above, triangle ABC is an isosceles triangle with AB = BC and BD is the perpendicular dropped from vertex B to the side AC where D is mid point of AB. Point E is marked on BD such that \(\angle\)DAE = 45 degree and \(\angle\)ECB =15 degree. What is the ratio of the area of triangle BEC to the area of the triangle ABC?


A) \(\frac{(3-√3)}{6}\)
B) \(\frac{(3+√3)}{4}\)
C) \(\frac{(5-√3)}{6}\)
D) \(\frac{(5+√3)}{3√3}\)
E) Cannot be determined

Weekly Quant Quiz #7 Question No 3


_________________

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

Manager
Manager
avatar
B
Joined: 16 Sep 2011
Posts: 92
GMAT ToolKit User Reviews Badge
Re: Please refer to the figure above, triangle ABC is an isosceles triang  [#permalink]

Show Tags

New post 03 Nov 2018, 09:21
BD is the perpendicular bisector, hence AD= CD
moreover angle BAE = angle BCD

triangle AED and triangle EDC are similar and congruent hence angle EAD = 45= angle ECD= 60


hence ABC is a equilateral triangle , hence AB= BC= AC, lets say it is a
AD = sqrt AB*AB - AD/2*AD/2 = sqrt 3/2a

in triangle ADE,
DE =AD = a/2
hence BE = BD-DE= sqrt3 /2 a - a/2

area(triangle BEC)/ area (triangle ABC) = (1/2*CD *BE) /(sqrt 3/4 a^2) = (1/2* a/2*(sqrt3 /2- 1/2) / (sqrt3/4 a^2)= sqrt 3 - 1/sqrt 3/ 2, multiplying sqrt 3 on Numerator and Denominator
gives option A
Manager
Manager
User avatar
B
Joined: 04 Jun 2018
Posts: 57
CAT Tests
Re: Please refer to the figure above, triangle ABC is an isosceles triang  [#permalink]

Show Tags

New post 03 Nov 2018, 10:00
It cannot be calculated ans E.
Intern
Intern
avatar
B
Joined: 09 Apr 2018
Posts: 12
Re: Please refer to the figure above, triangle ABC is an isosceles triang  [#permalink]

Show Tags

New post 03 Nov 2018, 10:00
Ans is a) its a little complicated but for area of triangle bec we subtract the area of BDC-DEC
so it is (1/2 * AB/2*ABroot3/2 )-1/2*AB/2*AB/2root2
--------------------------------------------------------
root3/2 * ABsquare
Manager
Manager
avatar
G
Joined: 14 Jun 2018
Posts: 180
CAT Tests
Re: Please refer to the figure above, triangle ABC is an isosceles triang  [#permalink]

Show Tags

New post 04 Nov 2018, 01:05
ABC is an equilateral triangle.
Assume side = 10
Area of ABC = 25√3

BD = 10√3 / 2 = 5√3
BD = BE + ED
BE = 5√3 - 5 = 5(√3 - 1)

Area of BEA = 1/2 * BE * DC = 25(√3 - 1) / 2

BEA / ABC = 25(√3 - 1) / 2* 25√3

= (√3 - 1)/ 2√3
Multiply num and deno with √3
3-√3 / 6

A
Attachments

q3.PNG
q3.PNG [ 50.05 KiB | Viewed 197 times ]

GMAT Club Bot
Re: Please refer to the figure above, triangle ABC is an isosceles triang &nbs [#permalink] 04 Nov 2018, 01:05
Display posts from previous: Sort by

Please refer to the figure above, triangle ABC is an isosceles triang

  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®.