It is currently 24 Feb 2018, 07:35

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 the figure above, AB, which has length z cm, is tangent to the

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

Hide Tags

Top Contributor
Board of Directors
User avatar
G
Joined: 01 Sep 2010
Posts: 3483
In the figure above, AB, which has length z cm, is tangent to the [#permalink]

Show Tags

New post 26 Jul 2017, 07:58
Top Contributor
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

79% (01:47) correct 21% (01:37) wrong based on 201 sessions

HideShow timer Statistics

Image
In the figure above, AB, which has length z cm, is tangent to the circle at point A, and BD, which has length y cm, intersects the circle at point C. If BC = x cm and \(z = \sqrt{xy}\), what is the value of x ?

(1) CD = x cm

(2) \(z = 5 \sqrt{2}\)


[Reveal] Spoiler:
Attachment:
circle.jpg
circle.jpg [ 18.64 KiB | Viewed 1311 times ]
[Reveal] Spoiler: OA

_________________

COLLECTION OF QUESTIONS AND RESOURCES
Quant: 1. ALL GMATPrep questions Quant/Verbal 2. Bunuel Signature Collection - The Next Generation 3. Bunuel Signature Collection ALL-IN-ONE WITH SOLUTIONS 4. Veritas Prep Blog PDF Version 5. MGMAT Study Hall Thursdays with Ron Quant Videos
Verbal:1. Verbal question bank and directories by Carcass 2. MGMAT Study Hall Thursdays with Ron Verbal Videos 3. Critical Reasoning_Oldy but goldy question banks 4. Sentence Correction_Oldy but goldy question banks 5. Reading-comprehension_Oldy but goldy question banks


Last edited by Bunuel on 26 Jul 2017, 08:00, edited 1 time in total.
Formatted the question.
Intern
Intern
avatar
B
Joined: 28 Apr 2017
Posts: 41
In the figure above, AB, which has length z cm, is tangent to the [#permalink]

Show Tags

New post 26 Jul 2017, 13:51
Sol- we are given and also by second theorem that z^2=xy
1- this gives y=2x--> z^2=2x^2
2-\(z=5\sqrt{2}\)...not given x or y

Combining we know
\(5\sqrt{2}^2=2x^2\)
Intern
Intern
avatar
B
Joined: 27 Dec 2017
Posts: 25
Re: In the figure above, AB, which has length z cm, is tangent to the [#permalink]

Show Tags

New post 18 Jan 2018, 23:14
From 1 statement we know y = 2x
And then z = x√3 but to calculate z we need it's value
From 2 statement we know will get z
So it's together sufficient

study mode
Intern
Intern
User avatar
B
Joined: 25 Jan 2016
Posts: 18
Location: India
GPA: 3.9
WE: Engineering (Consulting)
Re: In the figure above, AB, which has length z cm, is tangent to the [#permalink]

Show Tags

New post 19 Jan 2018, 00:33
carcass , Can you please let us know . How this question can be solved.

Thanks.
Intern
Intern
avatar
B
Joined: 01 Nov 2017
Posts: 11
CAT Tests
Re: In the figure above, AB, which has length z cm, is tangent to the [#permalink]

Show Tags

New post 19 Jan 2018, 03:08
Given: z = Root(X*Y) -> to answer question we need to have information about z and y

1) y = 2x -> z=Root(x*2x) = Root (2x^2) = x*root(2) -> however INSUFF. as we have no information about x
2) z=5*root(2) clearly Insuff as we don't have any details about x or y

However combining (1) + (2) you get x*root(2) = 5*root(2) => x=5 , therefor SUFFICIENT
DS Forum Moderator
avatar
G
Joined: 21 Aug 2013
Posts: 805
Location: India
Premium Member CAT Tests
Re: In the figure above, AB, which has length z cm, is tangent to the [#permalink]

Show Tags

New post 19 Jan 2018, 05:53
prashant0099 wrote:
carcass , Can you please let us know . How this question can be solved.

Thanks.


Hi

You can go through the solutions posted in this thread.
You can also read about circles theory here:

https://gmatclub.com/forum/math-circles-87957.html
Re: In the figure above, AB, which has length z cm, is tangent to the   [#permalink] 19 Jan 2018, 05:53
Display posts from previous: Sort by

In the figure above, AB, which has length z cm, is tangent to the

  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®.