Last visit was: 24 Apr 2024, 05:22 It is currently 24 Apr 2024, 05:22

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
SORT BY:
Kudos
Tags:
Show Tags
Hide Tags
GMAT Club Legend
GMAT Club Legend
Joined: 08 Jul 2010
Status:GMAT/GRE Tutor l Admission Consultant l On-Demand Course creator
Posts: 5957
Own Kudos [?]: 13386 [2]
Given Kudos: 124
Location: India
GMAT: QUANT+DI EXPERT
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
WE:Education (Education)
Send PM
avatar
Intern
Intern
Joined: 10 Jan 2013
Posts: 36
Own Kudos [?]: 10 [1]
Given Kudos: 5
Location: United States
Concentration: General Management, Operations
GMAT 1: 710 Q49 V38
GPA: 3.02
WE:Design (Telecommunications)
Send PM
GMAT Club Legend
GMAT Club Legend
Joined: 08 Jul 2010
Status:GMAT/GRE Tutor l Admission Consultant l On-Demand Course creator
Posts: 5957
Own Kudos [?]: 13386 [1]
Given Kudos: 124
Location: India
GMAT: QUANT+DI EXPERT
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
WE:Education (Education)
Send PM
Board of Directors
Joined: 17 Jul 2014
Posts: 2163
Own Kudos [?]: 1180 [0]
Given Kudos: 236
Location: United States (IL)
Concentration: Finance, Economics
GMAT 1: 650 Q49 V30
GPA: 3.92
WE:General Management (Transportation)
Send PM
If l and w represent the length and width, respectively, of the rectan [#permalink]
i spent more time on thinking whether B is a trap or not, since 10 is 2x5, and we know the pythagorean triplet 3-4-5 multiplied by 2 or 6-8-10.
even the first statement might suggest that l=8 and w=6 since 6*8 = 48
but!!!
if you do the math, you see that lw = 48, and l^2 + w^2 = 100
knowing that (a+b)^2 = a^2+2ab+b^2, we can easily see that l^2+2lw+w^2 = 196 or (l+w)^2 = 196
l+w will thus be 14 and the perimeter 32. we can get to the correct answer only by combining the two statements.
C is the answer.
Intern
Intern
Joined: 06 Nov 2017
Status:Prepping for GMAT
Posts: 22
Own Kudos [?]: 14 [1]
Given Kudos: 34
Location: France
GPA: 4
Send PM
If l and w represent the length and width, respectively, of the rectan [#permalink]
1
Bookmarks
GMATinsight wrote:
If l and w represent the length and width, respectively, of the rectangle, what is the perimeter of Rectangle?

(1) The area of the rectangle is 48.
(2) The length of a diagonal of the rectangle is 10.


Rephrasing the question: "what is the perimeter of the rectangle?" i.e. \(2*(l+w) = ?\)

(1) The area of the rectangle is 48
Mathematically, this means that \(l*w = 48\). This piece of information is not sufficient by itself.
Hence, the statement is insufficient (eliminate A and D).

(2) The length of a diagonal of the rectangle is 10
Since rectangles have right angles in their corners, the diagonal of any rectangle can be obtained through Pythagoras' theorem. Mathematically, this means that \(\sqrt{l^2+w^2} = 10\). This piece of information is not sufficient by itself.
Hence, the statement is insufficient (eliminate B).

(1) + (2) The area of the rectangle is 48 and the length of a diagonal of the rectangle is 10
This statement gives us two mathematical formulas:
\(l*w = 48\)
\(\sqrt{l^2+w^2} = 10\)
If one recalls, one of the basic mathematical identities is \((a+b)^2 = a^2 + 2*ab + b^2\). Hence, if we plug the two formulas above into the latter identity, we get:
\((l+w)^2 = l^2 + w^2 + 2*l*w = 10^2 + 2*48 = 196 = 14^2\)
Thus, \(2*(l+w) = 2*14 = 28\).
This is sufficient to answer the question.

Answer: C
GMAT Club Bot
If l and w represent the length and width, respectively, of the rectan [#permalink]
Moderator:
Math Expert
92901 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne