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

It is currently 25 Apr 2019, 18:57

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

If B is the midpoint of AC, what is the length of BE?

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

Hide Tags

 
Senior Manager
Senior Manager
avatar
Status: Do and Die!!
Joined: 15 Sep 2010
Posts: 256
If B is the midpoint of AC, what is the length of BE?  [#permalink]

Show Tags

New post 15 Nov 2010, 12:00
3
8
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

59% (01:19) correct 41% (01:32) wrong based on 310 sessions

HideShow timer Statistics

Attachment:
geo.JPG
geo.JPG [ 3.23 KiB | Viewed 3360 times ]
If B is the midpoint of AC, what is the length of BE?

(1) Angel BAE=30
(2) CD = \(\sqrt{20}\)

_________________
I'm the Dumbest of All !!
Most Helpful Expert Reply
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 54544
Re: Geo  [#permalink]

Show Tags

New post 15 Nov 2010, 12:36
2
4
shrive555 wrote:
If B is the midpoint of AC, what is the length of BE?

(1) Angel BAE=30
(2) CD = \(\sqrt{20}\)


why 1 isn't enough ?


As angle E=Angle D then BE||CD. Now as B is the midpoint of AC and BE||CD then BE becomes a midsegment (a line segment joining the midpoints of two sides of a triangle). The property of midsegemnt: the midsegment is always half the length of the third side. So 2BE=CD.

(1) Angel BAE=30 --> triangles BAE and CAD are 30-60-90 triangles where BE is a midsegment. We know only angles but not the lengths, so can not find BE. Not sufficient.

(2) \(CD= \sqrt{20}\) --> as 2BE=CD then \(BE=\frac{CD}{2}=\sqrt{5}\). Sufficient.

Answer: B.

Check triangles chapter of Math Book for more on this topic: math-triangles-87197.html

Hope it helps.
_________________
General Discussion
Senior Manager
Senior Manager
avatar
Status: Do and Die!!
Joined: 15 Sep 2010
Posts: 256
Re: Geo  [#permalink]

Show Tags

New post 15 Nov 2010, 12:48
Thanks B, Well i was thinking that we know about 30,60,90 as 1:/sqr3:2 ..... But these are ratios of sides only NOT the lengths.
_________________
I'm the Dumbest of All !!
Veritas Prep GMAT Instructor
User avatar
D
Joined: 16 Oct 2010
Posts: 9146
Location: Pune, India
Re: Geo  [#permalink]

Show Tags

New post 16 Nov 2010, 20:12
2
shrive555 wrote:
If B is the midpoint of AC, what is the length of BE?

(1) Angel BAE=30
(2) CD = \(\sqrt{20}\)


why 1 isn't enough ?


Triangles ABE and ACD are similar (because all corresponding angles are equal)
Since AB is 1/2 of AC, length of BE will be half of length of CD. To know the length of BE, you only need the length of CD.

Knowing only the angle BAE doesn't help because we do not have the length of any side available.
_________________
Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >
Manager
Manager
User avatar
Joined: 17 Jun 2015
Posts: 204
GMAT 1: 540 Q39 V26
GMAT 2: 680 Q46 V37
GMAT ToolKit User
Re: If B is the midpoint of AC, what is the length of BE?  [#permalink]

Show Tags

New post 19 Dec 2015, 22:04
The two triangles are similar because of the AAA similarity.

Statement 1 only gives the ratio.

Statement 2: Gives a value and thus the side length too.

Hence B
_________________
Fais de ta vie un rêve et d'un rêve une réalité
Senior Manager
Senior Manager
User avatar
P
Joined: 29 Jun 2017
Posts: 454
GPA: 4
WE: Engineering (Transportation)
GMAT ToolKit User Reviews Badge
Re: If B is the midpoint of AC, what is the length of BE?  [#permalink]

Show Tags

New post 31 Aug 2017, 01:24
Ans is B
AB/AC = BE/CD
AB / AB+BC
AB/2AB
1/2 = BE/CD
CD =√20
BE can be calculated

for statement 1) Value of no side is given hence cant be determined

Ans is B
_________________
Give Kudos for correct answer and/or if you like the solution.
GMAT Club Bot
Re: If B is the midpoint of AC, what is the length of BE?   [#permalink] 31 Aug 2017, 01:24
Display posts from previous: Sort by

If B is the midpoint of AC, what is the length of BE?

  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®.