NEW HERE? LEARN MORE
closeclose
Last visit was: 02 May 2024, 12:33 It is currently 02 May 2024, 12:33
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

Is DE parallel to BC ? DB = AD. (1) AE = EC (2) DB = EC

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 93010
Own Kudos [?]: 620765 [10]
Given Kudos: 81730
Send PM
CAT Tests Forum Quiz Mode
Is DE parallel to BC ? DB = AD. (1) AE = EC (2) DB = EC [#permalink] New post   17 Oct 2017, 23:48
10
Bookmarks
Expert Reply
00:00
A
B
C
D
E

Difficulty:

65% (hard)

Question Stats:

44% (01:23) correct 56% (01:43) wrong based on 140 sessions
Hide Show timer Statistics

If DB = AD, is DE parallel to BC ?

(1) AE = EC
(2) DB = EC


Show Spoiler
Attachment:
2017-10-18_1046.png
2017-10-18_1046.png [ 3.9 KiB | Viewed 6938 times ]
ShowHide Answer
Official Answer
A
User avatar
S
Alexey1989x
Manager
Manager
Joined: 05 Dec 2016
Posts: 194
Own Kudos [?]: 88 [0]
Given Kudos: 49
Concentration: Strategy, Finance
GMAT 1: 620 Q46 V29
Send PM
GMAT ToolKit User
Re: Is DE parallel to BC ? DB = AD. (1) AE = EC (2) DB = EC [#permalink] New post   18 Oct 2017, 02:57
(1) AED is similar to ABC, hence angle ADE= angle ABC which means that DE is parallel to BC
(2) From here we cannot deduce whether AE=EC, so Insufficient

Answer A
avatar
B
manishgmat1
Intern
Intern
Joined: 11 Mar 2014
Posts: 19
Own Kudos [?]: 4 [1]
Given Kudos: 8
Schools: HEC Montreal '20
Send PM
Reviews Badge
Re: Is DE parallel to BC ? DB = AD. (1) AE = EC (2) DB = EC [#permalink] New post   18 Oct 2017, 03:16
1
Kudos
a line parallel to one side of triangle divides the other two sides in equal proportion
hence a is sufficient
considering b
given CE=BD
but the bottom or base angles of triangle might be diff hence the lengths of sides CE and BD cant be confirmed
User avatar
B
Plunkster82
Manager
Manager
Joined: 09 Aug 2017
Posts: 56
Own Kudos [?]: 23 [0]
Given Kudos: 18
Location: United States
Concentration: Technology
GMAT 1: 640 Q44 V33
GMAT 2: 630 Q47 V29
WE:Research (Investment Banking)
Send PM
Re: Is DE parallel to BC ? DB = AD. (1) AE = EC (2) DB = EC [#permalink] New post   23 Oct 2017, 18:30
E, I screwed this one up. Not a silly mistake, just a knowledge gap.

The missing link for me was to see that the angles of the smaller triangle were similar to the larger triangle.
avatar
P
Shobhit7
Manager
Manager
Joined: 01 Feb 2017
Posts: 246
Own Kudos [?]: 346 [0]
Given Kudos: 148
Send PM
Is DE parallel to BC ? DB = AD. (1) AE = EC (2) DB = EC [#permalink] New post   24 Oct 2017, 14:30
By Applying Midpoint Theorem, we can determine with the help of Statement 1 alone that DE is parallel to BC.

Statement 2 is Insufficient to provide proof of triangle similarity.

Hence, Ans A

Posted from my mobile device
User avatar
S
Annie28
Intern
Intern
Joined: 05 Aug 2017
Posts: 22
Own Kudos [?]: 48 [1]
Given Kudos: 24
Location: Viet Nam
Annie: Nguyen
Concentration: International Business, Other
GPA: 3.33
WE:Supply Chain Management (Transportation)
Send PM
Is DE parallel to BC ? DB = AD. (1) AE = EC (2) DB = EC [#permalink] New post   24 Oct 2017, 20:19
1
Kudos
A

From (1) AED is similar to ABC => angle ADE= angle ABC => DE is parallel to BC=> suff
From (2) There will be insufficient condition to ensure AED is similar to ABC => insuff
avatar
B
Psk13
Intern
Intern
Joined: 23 Jul 2016
Posts: 21
Own Kudos [?]: 6 [0]
Given Kudos: 176
Send PM
Re: Is DE parallel to BC ? DB = AD. (1) AE = EC (2) DB = EC [#permalink] New post   02 Nov 2017, 10:51
Bunuel

how to prove that two lines are parallel? what should i look for ? interior angles to be supplementary?
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 93010
Own Kudos [?]: 620765 [0]
Given Kudos: 81730
Send PM
CAT Tests Forum Quiz Mode
Re: Is DE parallel to BC ? DB = AD. (1) AE = EC (2) DB = EC [#permalink] New post   02 Nov 2017, 22:58
Expert Reply
Psk13 wrote:
Bunuel

how to prove that two lines are parallel? what should i look for ? interior angles to be supplementary?


From (1) DE turns out to be a Midsegment of a Triangle (A line segment joining the midpoints of two sides of a triangle).

• The midsegment is always parallel to the third side of the triangle.
• The midsegment is always half the length of the third side.
User avatar
bumpbot
Non-Human User
Joined: 09 Sep 2013
Posts: 32791
Own Kudos [?]: 824 [0]
Given Kudos: 0
Send PM
Re: Is DE parallel to BC ? DB = AD. (1) AE = EC (2) DB = EC [#permalink] New post   08 Dec 2020, 14:00
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.
GMAT Club Bot
gmatclubot
Re: Is DE parallel to BC ? DB = AD. (1) AE = EC (2) DB = EC [#permalink]
08 Dec 2020, 14:00
Moderator:
Bunuel
Math Expert
93010 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions