Find all School-related info fast with the new School-Specific MBA Forum

It is currently 06 Jul 2015, 04:15

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If the area of triangular region RST is 25, what is the

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
1 KUDOS received
Director
Director
avatar
Joined: 05 Jan 2008
Posts: 707
Followers: 3

Kudos [?]: 158 [1] , given: 0

If the area of triangular region RST is 25, what is the [#permalink] New post 21 May 2008, 01:53
1
This post received
KUDOS
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

54% (01:56) correct 46% (01:09) wrong based on 202 sessions
If the area of triangular region RST is 25, what is the perimeter of RST?

(1) The length of one side of RST is \(5\sqrt{2}\).
(2) RST is a right isosceles triangle.
[Reveal] Spoiler: OA

_________________

Persistence+Patience+Persistence+Patience=G...O...A...L


Last edited by Bunuel on 25 Oct 2013, 06:45, edited 1 time in total.
Edited the question and added the OA
SVP
SVP
avatar
Joined: 04 May 2006
Posts: 1936
Schools: CBS, Kellogg
Followers: 19

Kudos [?]: 490 [0], given: 1

Premium Member
Re: DS2-24 [#permalink] New post 21 May 2008, 02:21
prasannar wrote:
24. If the area of triangular region RST is 25, what is the perimeter of RST?
(1) The length of one side of RST is 5 sqrt 2.
(2) RST is a right isosceles triangle.

Plz explain


B

1/2*a^2 = 25 --> a =?
then b =a*sqare root(2)

and perimeter = b+ 2a, suff
_________________

GMAT Club Premium Membership - big benefits and savings

VP
VP
User avatar
Joined: 18 May 2008
Posts: 1296
Followers: 14

Kudos [?]: 192 [0], given: 0

Re: DS2-24 [#permalink] New post 21 May 2008, 02:30
(1) The length of one side is given . but no information abt other sides. Insufficient
(2)The triangle is right isosceles let one side be x So area=1/2 *base*height=25.
here base=height (isoscels triagle)=x
Therefore, 1/2 *x*x=25 so x can be found
since right triangle so third side can be found say y
Perimeter is 2x+y
So sufficient
Hence answer is B
Intern
Intern
avatar
Joined: 07 May 2008
Posts: 19
Followers: 0

Kudos [?]: 1 [0], given: 0

Re: DS2-24 [#permalink] New post 21 May 2008, 02:47
The question stem tells us that 1/2 * b * h = 25 and asks us to determine what RS + ST + TR is.

(1) Statement just tells us what one of the 3 sides is where the b and h could still take several values and affect the other two sides:

Insufficient

(2) This statement simply tells us that b = h so b^2 = 50. If we know the lengths of two sides of a right triangle, then we can determine (I won't calculate it here since it would be a waste of time on test day) the length of the other. So:

Sufficient

Answer = [B]
_________________

Ryan S.
| GMAT Instructor |
Elite GMAT Preparation and Admissions Consulting
http://www.VeritasPrep.com

Current Student
avatar
Joined: 28 Dec 2004
Posts: 3387
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 14

Kudos [?]: 186 [0], given: 2

Re: DS2-24 [#permalink] New post 21 May 2008, 05:47
I think C is right..how do we know from B which side is base?

i mean i could have a 90-degree-45-45 isso triangle and it will have perimeter of 10+5+5=20..

i could have a different isso triangle..
SVP
SVP
avatar
Joined: 28 Dec 2005
Posts: 1579
Followers: 2

Kudos [?]: 91 [0], given: 2

Re: DS2-24 [#permalink] New post 21 May 2008, 13:05
i dont get it ... from B, you know that base=height=5*root(2) .... and since its a right isoceles, the hypotenuse will be 10 ... wont it ?
Current Student
avatar
Joined: 28 Dec 2004
Posts: 3387
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 14

Kudos [?]: 186 [0], given: 2

Re: DS2-24 [#permalink] New post 21 May 2008, 13:46
pmenon wrote:
i dont get it ... from B, you know that base=height=5*root(2) .... and since its a right isoceles, the hypotenuse will be 10 ... wont it ?



no it wont..just draw a 3-4-5 right angle tirangle or a 5-12-13 right angle,triangle..
SVP
SVP
avatar
Joined: 28 Dec 2005
Posts: 1579
Followers: 2

Kudos [?]: 91 [0], given: 2

Re: DS2-24 [#permalink] New post 21 May 2008, 14:28
but a 3-4-5 isnt an isoceles triangle ... or am i missing something ?
Manager
Manager
avatar
Joined: 21 Mar 2008
Posts: 81
Followers: 1

Kudos [?]: 8 [0], given: 0

Re: DS2-24 [#permalink] New post 21 May 2008, 14:39
fresinha12 wrote:
pmenon wrote:
i dont get it ... from B, you know that base=height=5*root(2) .... and since its a right isoceles, the hypotenuse will be 10 ... wont it ?



no it wont..just draw a 3-4-5 right angle tirangle or a 5-12-13 right angle,triangle..


Doesn't a right isosceles triangle means that the two equal sides make up the right angle?
Manager
Manager
avatar
Joined: 19 May 2008
Posts: 165
Location: Mumbai
Followers: 1

Kudos [?]: 7 [0], given: 0

Re: DS2-24 [#permalink] New post 21 May 2008, 19:31
the answer should be B since in a right isosceles triangle, base = height and area is (base*height)/2 - so we can get both the sides and then hypotenuse is side*sqrt 2 - so I am a bit surprised that the answer is C - it is anyway not A and D. E is also out of the question.
Manager
Manager
avatar
Joined: 10 Mar 2008
Posts: 67
Followers: 2

Kudos [?]: 25 [0], given: 0

Re: DS2-24 [#permalink] New post 21 May 2008, 20:47
fresinha12 wrote:
I think C is right..how do we know from B which side is base?

i mean i could have a 90-degree-45-45 isso triangle and it will have perimeter of 10+5+5=20..

i could have a different isso triangle..


hi fresinha12,
is it required to know whats the base???
in any case let what ever be the base the area will be same
Attachments

tringle.JPG
tringle.JPG [ 36.1 KiB | Viewed 2793 times ]

SVP
SVP
User avatar
Joined: 06 Sep 2013
Posts: 2046
Concentration: Finance
GMAT 1: 770 Q0 V
Followers: 26

Kudos [?]: 314 [0], given: 355

GMAT ToolKit User
Re: DS2-24 [#permalink] New post 25 Oct 2013, 05:40
rohit929 wrote:
fresinha12 wrote:
I think C is right..how do we know from B which side is base?

i mean i could have a 90-degree-45-45 isso triangle and it will have perimeter of 10+5+5=20..

i could have a different isso triangle..


hi fresinha12,
is it required to know whats the base???
in any case let what ever be the base the area will be same


I agree with Rohit, you can change the position but the relative sides will be the same hence you can trace a perpendicular for the height wherever you want and you would still have the same area and same perimeter.

Hence for me (B) is the correct choce
Let us know if this is the OA will you?
Thanks
Cheers
J :)
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 28316
Followers: 4482

Kudos [?]: 45332 [0], given: 6740

Re: DS2-24 [#permalink] New post 25 Oct 2013, 06:51
Expert's post
jlgdr wrote:
rohit929 wrote:
fresinha12 wrote:
If the area of triangular region RST is 25, what is the perimeter of RST?

(1) The length of one side of RST is \(5\sqrt{2}\).
(2) RST is a right isosceles triangle.

I think C is right..how do we know from B which side is base?

i mean i could have a 90-degree-45-45 isso triangle and it will have perimeter of 10+5+5=20..

i could have a different isso triangle..


hi fresinha12,
is it required to know whats the base???
in any case let what ever be the base the area will be same


I agree with Rohit, you can change the position but the relative sides will be the same hence you can trace a perpendicular for the height wherever you want and you would still have the same area and same perimeter.

Hence for me (B) is the correct choce
Let us know if this is the OA will you?
Thanks
Cheers
J :)


The correct answer is B. From (2) we know that 1/2*leg^2=25 --> we can get the length of the legs, and since it's a 45-45-90 right isosceles triangle, we can get the length of the hypotenuse too.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

GMAT Club Premium Membership - big benefits and savings

Manager
Manager
User avatar
Joined: 10 Mar 2013
Posts: 238
Followers: 1

Kudos [?]: 32 [0], given: 2068

Re: If the area of triangular region RST is 25, what is the [#permalink] New post 07 Dec 2013, 10:57
I don't understand why (1) is not sufficient. Doesn't (1) imply that the triangle is an isosceles right triangle since the height = 5*sqrt(2)?
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 28316
Followers: 4482

Kudos [?]: 45332 [0], given: 6740

Re: If the area of triangular region RST is 25, what is the [#permalink] New post 08 Dec 2013, 06:03
Expert's post
TooLong150 wrote:
I don't understand why (1) is not sufficient. Doesn't (1) imply that the triangle is an isosceles right triangle since the height = 5*sqrt(2)?


No. Any triangle with the base (side) of \(5\sqrt{2}\) and height of \(\frac{10}{\sqrt{2}}\) would have the area of 25.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

GMAT Club Premium Membership - big benefits and savings

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 5383
Followers: 311

Kudos [?]: 60 [0], given: 0

Premium Member
Re: If the area of triangular region RST is 25, what is the [#permalink] New post 09 Dec 2014, 14:42
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 Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Intern
Intern
User avatar
Joined: 21 Apr 2014
Posts: 41
Followers: 1

Kudos [?]: 8 [0], given: 0

If the area of triangular region RST is 25, what is the [#permalink] New post 15 Feb 2015, 02:00
So the prompt tells us that the area of a triangle is 25 or that b*h=50
we are looking for the perimeter

(I) doesn't really tell us anything. Giving us one side is useless because we have no idea what the other sides could be
(II) actually tells us quite a lot. The fact that it is an isosceles right triangle tells us that b=h, so we know that those sides are rt(50) long and we can use that information to figure out the hypotenuse and add them up to get the perimeter.
_________________

Eliza
GMAT Tutor
bestgmatprepcourse.com

If the area of triangular region RST is 25, what is the   [#permalink] 15 Feb 2015, 02:00
    Similar topics Author Replies Last post
Similar
Topics:
2 Experts publish their posts in the topic In the figure above, if the area of triangular region D is 4 Walkabout 5 18 Dec 2012, 05:58
6 Experts publish their posts in the topic What is the area of triangular region ABC above? Walkabout 8 03 Dec 2012, 03:54
67 Experts publish their posts in the topic In the figure above, is the area of triangular region ABC jfk 24 09 Jun 2012, 23:28
If the area of traingleular region RST is 25, what is the el1981 4 30 Oct 2007, 10:40
What is the area of the rectangular region? PICTURE: jimmyjamesdonkey 5 28 Oct 2007, 10:30
Display posts from previous: Sort by

If the area of triangular region RST is 25, what is the

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

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®.