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

It is currently 25 Oct 2014, 16:41

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

In measuring the sides of a rectangle, one side

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 25 Jan 2013
Posts: 24
Followers: 0

Kudos [?]: 7 [0], given: 11

In measuring the sides of a rectangle, one side [#permalink] New post 20 Feb 2013, 21:02
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

87% (02:07) correct 13% (00:54) wrong based on 59 sessions
In measuring the sides of a rectangle, one side is taken 8% in excess and other 5% in deficit. Find the error percentage in the area calculated from these measurements.

A. 3.5%
B. 2.4%
C. 3%
D. 5%
E. 2.6%
[Reveal] Spoiler: OA
Intern
Intern
avatar
Joined: 18 Jan 2013
Posts: 2
Followers: 0

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

Re: In measuring the sides of a rectangle, one side [#permalink] New post 20 Feb 2013, 21:43
antoxavier wrote:
In measuring the sides of a rectangle, one side is taken 8% in excess and other 5% in deficit. Find the error percentage in the area calculated from these measurements.

A. 3.5%
B. 2.4%
C. 3%
D. 5%
E. 2.6%


Let the sides of the rectangle be a and b.

actual area of the rectangle without error = ab

New side a ( 8% in excess) = a+0.08a = 1.08a
New side b ( 5% in deficit) = b-0.05b = 0.95b

Area of the new rectangle = (1.08a)(0.95b)= (1.0260)ab
say a=1 and b=1
area of the original rectangle = 1
area of the new rectangle = 1.026
change in the area calculation = .026
error percentage in the area calculated = 2.6%

Let me know otherwise.
Cheers
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23422
Followers: 3617

Kudos [?]: 28975 [0], given: 2874

Re: In measuring the sides of a rectangle, one side [#permalink] New post 21 Feb 2013, 02:36
Expert's post
antoxavier wrote:
In measuring the sides of a rectangle, one side is taken 8% in excess and other 5% in deficit. Find the error percentage in the area calculated from these measurements.

A. 3.5%
B. 2.4%
C. 3%
D. 5%
E. 2.6%


Say both sides of the rectangle are equal to 100 (so consider that we have a square). In this case the area is 100*100=10,000.

Now, the area obtained with wrong measurements would be 108*95=10,260, which is 2.6% greater than the actual area.

Answer: E.
_________________

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

Get the best GMAT Prep Resources with GMAT Club Premium Membership

1 KUDOS received
Manager
Manager
avatar
Joined: 25 Sep 2012
Posts: 215
Followers: 0

Kudos [?]: 61 [1] , given: 156

GMAT ToolKit User Reviews Badge CAT Tests
Re: In measuring the sides of a rectangle, one side [#permalink] New post 09 Jun 2014, 10:39
1
This post received
KUDOS
Percentage Change Formula
if there are two succesive changes to a quantity ( as in this case ) you can solve it by a simple formula
net change = a + b + \frac{ab}{100}
e.g. net change of to increase of 50% = 50 + 50 + \frac{2500}{100} = 125
net change of increase in 8% and decrease of 5 % = 8 - 5 -\frac{8*5}{100} = 2.6
Re: In measuring the sides of a rectangle, one side   [#permalink] 09 Jun 2014, 10:39
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic If the sides of a rectangle are increased by 15% antoxavier 2 20 Feb 2013, 21:37
4 Experts publish their posts in the topic In the rectangle above, A is the midpoint of the side, and DeeptiM 6 15 Aug 2011, 01:57
In the xy-plane, the sides of a certain rectangle are aurobindo 4 14 Feb 2007, 05:00
There is a rectangle such that one side is two times of the gamjatang 6 17 Nov 2005, 18:30
5 Find the area of a rhombus one side of which measures 20 anirban16 4 23 Mar 2005, 14:31
Display posts from previous: Sort by

In measuring the sides of a rectangle, one side

  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®.