It is currently 19 Oct 2017, 11:30

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# If p is the perimeter of rectangle Q, what is the value of

Author Message
Intern
Joined: 07 Jul 2008
Posts: 12

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

If p is the perimeter of rectangle Q, what is the value of [#permalink]

### Show Tags

08 Jul 2008, 23:17
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

If p is the perimeter of rectangle Q, what is the value of p?

1. Each diagonal of rectangle Q has length 10

2. The area of rectangle Q is 48

----
Here's my question.
Doesn't "(1) Each diagonal"... imply that 2 diagonals cross in a square and that you can assume equal lengths of 5 for each bisected side? Graphically... \ and / = X

Thanks very much

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

Director
Joined: 27 May 2008
Posts: 541

Kudos [?]: 363 [0], given: 0

### Show Tags

09 Jul 2008, 00:01
fwl200 wrote:
If p is the perimeter of rectangle Q, what is the value of p?

1. Each diagonal of rectangle Q has length 10

2. The area of rectangle Q is 48

----
Here's my question.
Doesn't "(1) Each diagonal"... imply that 2 diagonals cross in a square and that you can assume equal lengths of 5 for each bisected side? Graphically... \ and / = X

Thanks very much

answer to your question : yes each diagonal will bisect each other in a rectangle, but that doesn not mean that its a square. For it to be square, diagonals should bisect each other and andgle between them should be 90.

Now lest solve the question

if x and y are the two sides. we have to find out 2(x+y)

statement 1 : $$[m]x^2 + y^2 = 100$$[/m] . there coudl be more than one possible solution for (x,y) not suff
statement 2 : xy = 48, again not suff

combine : we know (x+y)^2 = x^2 + y^2 +2xy
mean we can find out x+y... Suff

Kudos [?]: 363 [0], given: 0

Director
Joined: 14 Aug 2007
Posts: 726

Kudos [?]: 212 [0], given: 0

### Show Tags

09 Jul 2008, 00:03
fwl200 wrote:
If p is the perimeter of rectangle Q, what is the value of p?

1. Each diagonal of rectangle Q has length 10

2. The area of rectangle Q is 48

----
Here's my question.
Doesn't "(1) Each diagonal"... imply that 2 diagonals cross in a square and that you can assume equal lengths of 5 for each bisected side? Graphically... \ and / = X

Thanks very much

for 1) consider a rectangle of 8x6 or a square of length 10/sqrt(2), both have diagonal of 10 , but perimeters are different.

Kudos [?]: 212 [0], given: 0

Senior Manager
Joined: 07 Jan 2008
Posts: 398

Kudos [?]: 290 [0], given: 0

### Show Tags

09 Jul 2008, 05:44
fwl200 wrote:
If p is the perimeter of rectangle Q, what is the value of p?

1. Each diagonal of rectangle Q has length 10

2. The area of rectangle Q is 48

----
Here's my question.
Doesn't "(1) Each diagonal"... imply that 2 diagonals cross in a square and that you can assume equal lengths of 5 for each bisected side? Graphically... \ and / = X

Thanks very much

1. Rectangular has two diagonals which have the same length ==> the rectangular must be square.
So the perimeter = 4*(10/2)*aqrt(2)

2. area = 48, hmm we can not determine the length and width of rectangular.

Kudos [?]: 290 [0], given: 0

Intern
Joined: 09 Jul 2008
Posts: 2

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

### Show Tags

09 Jul 2008, 06:05
as said, the figure can be square too,
When combining 1 and 2 we can get the values by solving quadratic equations.
We get either 6 or 8.

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

Current Student
Joined: 04 Jan 2005
Posts: 283

Kudos [?]: 140 [0], given: 3

Location: Milan
Schools: Wharton, LBS, UChicago, Kellogg MMM (Donald Jacobs Scholarship), Stanford, HBS

### Show Tags

09 Jul 2008, 09:10
alpha_plus_gamma wrote:

for 1) consider a rectangle of 8x6 or a square of length 10/sqrt(2), both have diagonal of 10 , but perimeters are different.

The square of length 10/sqrt(2) would not have an area of 48 - would be 50.

Quote:
combine : we know (x+y)^2 = x^2 + y^2 +2xy

I can't get how you arrive to this equation combining the two statements, can you expand on this?

Kudos [?]: 140 [0], given: 3

Director
Joined: 27 May 2008
Posts: 541

Kudos [?]: 363 [0], given: 0

### Show Tags

09 Jul 2008, 09:15
alpha_plus_gamma wrote:

for 1) consider a rectangle of 8x6 or a square of length 10/sqrt(2), both have diagonal of 10 , but perimeters are different.

The square of length 10/sqrt(2) would not have an area of 48 - would be 50.

Quote:
combine : we know (x+y)^2 = x^2 + y^2 +2xy

I can't get how you arrive to this equation combining the two statements, can you expand on this?

we dint arrive at this equation by combining, We already know its a formula.

we need to find out (x+y). from combining the two statements we know x^2+y^2 from (1) and xy from (2) soe we can find out (x+y) using above formula.

Kudos [?]: 363 [0], given: 0

Current Student
Joined: 04 Jan 2005
Posts: 283

Kudos [?]: 140 [0], given: 3

Location: Milan
Schools: Wharton, LBS, UChicago, Kellogg MMM (Donald Jacobs Scholarship), Stanford, HBS

### Show Tags

09 Jul 2008, 09:21
You're right - I just got confused by the "^" which we have to use in place of standard math notation!

Thanks

Kudos [?]: 140 [0], given: 3

Director
Joined: 27 May 2008
Posts: 541

Kudos [?]: 363 [0], given: 0

### Show Tags

09 Jul 2008, 09:23
You're right - I just got confused by the "^" which we have to use in place of standard math notation!

Thanks

I should have used maths formula function provided on this site
$$(x+y)^2 = x^2 + y^2 +2xy$$

Kudos [?]: 363 [0], given: 0

Senior Manager
Joined: 19 Mar 2008
Posts: 351

Kudos [?]: 68 [0], given: 0

### Show Tags

09 Jul 2008, 09:34
lexis wrote:
fwl200 wrote:
If p is the perimeter of rectangle Q, what is the value of p?

1. Each diagonal of rectangle Q has length 10

2. The area of rectangle Q is 48

----
Here's my question.
Doesn't "(1) Each diagonal"... imply that 2 diagonals cross in a square and that you can assume equal lengths of 5 for each bisected side? Graphically... \ and / = X

Thanks very much

1. Rectangular has two diagonals which have the same length ==> the rectangular must be square.
So the perimeter = 4*(10/2)*aqrt(2)

2. area = 48, hmm we can not determine the length and width of rectangular.

Who say this -> Rectangular has two diagonals which have the same length ==> the rectangular must be square. ?

Kudos [?]: 68 [0], given: 0

Intern
Joined: 07 Jul 2008
Posts: 12

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

### Show Tags

09 Jul 2008, 10:49
This comes from the 11th edition GMAT review book. The answer is C

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

Director
Joined: 14 Aug 2007
Posts: 726

Kudos [?]: 212 [0], given: 0

### Show Tags

09 Jul 2008, 18:16
alpha_plus_gamma wrote:

for 1) consider a rectangle of 8x6 or a square of length 10/sqrt(2), both have diagonal of 10 , but perimeters are different.

The square of length 10/sqrt(2) would not have an area of 48 - would be 50.

We are intersted in perimeter, not in area.

Above I was trying to say that since there are (atleast) 2 possibilities that the the rectangle can be a 8x6 rectangle or a square with side 10/sqrt(2), the perimeters will be different and thus 1) alone won't be suffcient.

Kudos [?]: 212 [0], given: 0

VP
Joined: 03 Apr 2007
Posts: 1340

Kudos [?]: 833 [0], given: 10

### Show Tags

10 Jul 2008, 00:03
fwl200 wrote:
If p is the perimeter of rectangle Q, what is the value of p?

1. Each diagonal of rectangle Q has length 10

2. The area of rectangle Q is 48

----
Here's my question.
Doesn't "(1) Each diagonal"... imply that 2 diagonals cross in a square and that you can assume equal lengths of 5 for each bisected side? Graphically... \ and / = X

Thanks very much

p=2(a+b) ; a+b =?

1.sqrt(a^2+b^2) = 10
NS
2.ab= 48
NS
from 1 and 2 we can solve for a and b

C

Kudos [?]: 833 [0], given: 10

Re: DS: Geometry   [#permalink] 10 Jul 2008, 00:03
Display posts from previous: Sort by