It is currently 17 Nov 2017, 20:21

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

Events & Promotions in June
Open Detailed Calendar

In ∆ ABC above, if DE is parallel to AC, then x =

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

Hide Tags

Expert Post
1 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42248

Kudos [?]: 132522 [1], given: 12324

In ∆ ABC above, if DE is parallel to AC, then x = [#permalink]

Show Tags

New post 24 Aug 2017, 23:51
1
This post received
KUDOS
Expert's post
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

90% (01:02) correct 10% (02:03) wrong based on 61 sessions

HideShow timer Statistics

Image
In ∆ ABC above, if DE is parallel to AC, then x =

(A) 70
(B) 50
(C) 40
(D) 30
(E) 20

[Reveal] Spoiler:
Attachment:
2017-08-25_1042_001.png
2017-08-25_1042_001.png [ 16.45 KiB | Viewed 648 times ]
[Reveal] Spoiler: OA

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 132522 [1], given: 12324

BSchool Forum Moderator
User avatar
D
Joined: 26 Feb 2016
Posts: 1594

Kudos [?]: 667 [0], given: 17

Location: India
Concentration: General Management, Leadership
WE: Sales (Retail)
Premium Member CAT Tests
Re: In ∆ ABC above, if DE is parallel to AC, then x = [#permalink]

Show Tags

New post 25 Aug 2017, 00:15
Image

Since DE is parallel to AC, Angle BDE = 60(corresponding angles)
Also, the third angle in the triangle is 180 - (60 + 80) = 40
Angle EDA = 180 - 40 = 140(Angles in a straight line sum to 180)

2y = 40(corresponding angles) => y = 20
In ∆EDA, x + y + 140 = 180
Therefore, x = 180 - 140 - 20 = 20(Option E)
_________________

Stay hungry, Stay foolish

2017-2018 MBA Deadlines

Class of 2020: Rotman Thread | Schulich Thread
Class of 2019: Sauder Thread

Kudos [?]: 667 [0], given: 17

1 KUDOS received
Manager
Manager
User avatar
S
Joined: 27 Dec 2016
Posts: 171

Kudos [?]: 44 [1], given: 202

Concentration: Social Entrepreneurship, Nonprofit
GPA: 3.65
WE: Sales (Consumer Products)
Premium Member CAT Tests
Re: In ∆ ABC above, if DE is parallel to AC, then x = [#permalink]

Show Tags

New post 25 Aug 2017, 11:02
1
This post received
KUDOS
Bunuel wrote:
Image
In ∆ ABC above, if DE is parallel to AC, then x =

(A) 70
(B) 50
(C) 40
(D) 30
(E) 20

[Reveal] Spoiler:
Attachment:
2017-08-25_1042_001.png


- Because DE parallel with AC, so X must be equal with y --> alternate angles.
- So, if we know Y, we know X (X=Y).
- From triangle ABC = 180-2Y-80-60=0 --> 2Y=40, Y=20.
- Thus X=20.

E.
_________________

There's an app for that - Steve Jobs.

Kudos [?]: 44 [1], given: 202

VP
VP
avatar
P
Joined: 26 Mar 2013
Posts: 1284

Kudos [?]: 296 [0], given: 165

Reviews Badge CAT Tests
Re: In ∆ ABC above, if DE is parallel to AC, then x = [#permalink]

Show Tags

New post 26 Aug 2017, 19:34
Bunuel wrote:
Image
In ∆ ABC above, if DE is parallel to AC, then x =

(A) 70
(B) 50
(C) 40
(D) 30
(E) 20

[Reveal] Spoiler:
Attachment:
2017-08-25_1042_001.png



Sum of angles in ∆ ABC =180

2y = 180 - 80 - 60 = 40..........y = 20

DE is parallel to AC......then y =x =20

Answer: E

Kudos [?]: 296 [0], given: 165

Expert Post
Target Test Prep Representative
User avatar
S
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 1806

Kudos [?]: 919 [0], given: 3

Location: United States (CA)
Re: In ∆ ABC above, if DE is parallel to AC, then x = [#permalink]

Show Tags

New post 29 Aug 2017, 17:24
Bunuel wrote:
Image
In ∆ ABC above, if DE is parallel to AC, then x =

(A) 70
(B) 50
(C) 40
(D) 30
(E) 20

[Reveal] Spoiler:
Attachment:
2017-08-25_1042_001.png


Because angles x and y are alternate interior angles, we see that angle x = angle y.

For triangle ABC, we can create the following equation:

80 + 60 + 2y = 180

2y = 40

y = 20

So x = 20.

Answer: E
_________________

Scott Woodbury-Stewart
Founder and CEO

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Kudos [?]: 919 [0], given: 3

Re: In ∆ ABC above, if DE is parallel to AC, then x =   [#permalink] 29 Aug 2017, 17:24
Display posts from previous: Sort by

In ∆ ABC above, if DE is parallel to AC, then x =

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


GMAT Club MBA Forum Home| About| Terms and Conditions| 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®.