What is the perimeter of quadrilateral Q?

This topic has expert replies
Legendary Member
Posts: 2276
Joined: Sat Oct 14, 2017 6:10 am
Followed by:3 members

What is the perimeter of quadrilateral Q?

by VJesus12 » Sun Apr 14, 2019 9:42 am

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

What is the perimeter of quadrilateral Q?

(1) Q is a rectangle.
(2) The area of Q is 25.

[spoiler]OA=E[/spoiler]

Source: Princeton Review

Legendary Member
Posts: 2898
Joined: Thu Sep 07, 2017 2:49 pm
Thanked: 6 times
Followed by:5 members

by Vincen » Sat Apr 20, 2019 5:44 am

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

What is the perimeter of quadrilateral Q?

(1) Q is a rectangle.
(2) The area of Q is 25.

OA=E

Source: Princeton Review
Hi Vjesus12.

The perimeter of the quadrilateral Q is given by \(p= w+x+y+z \), where \(w, x, y, z\) are the lengths of each side of the quadrilateral.

Statement 1:
(1) Q is a rectangle.
Since Q is a rectangle, then we have that \( w=y\) and \( x=z\), so the perimeter is \(p= 2x+2y\), but we don't know the values of \(x\) and \(y\). Hence, this statement is NOT SUFFICIENT.

Statement 2:
(2) The area of Q is 25.
Now, we don't know what type of quadrilateral Q is. So, we can't get anything from the area. Therefore, this statement is NOT SUFFICIENT.

Statement 1 and Statement 2:

If Q is a rectangle with area equal to 25, we can get several cases, for example,

(i) Q is a square of side 5, then the perimeter of Q is 20.
(ii) Q is a rectangle with sides 25/2 and 2 respectively, therefore the perimeter of Q is 29.

Since we've got two different answers then we conclude that using both statements is NOT SUFFICIENT.

In conclusion, the correct answer is the option _E_.

I hope it helps.

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Sat Apr 20, 2019 5:48 am

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

VJesus12 wrote:What is the perimeter of quadrilateral Q?

(1) Q is a rectangle.
(2) The area of Q is 25.

[spoiler]OA=E[/spoiler]

Source: Princeton Review
Target question: What is the perimeter of quadrilateral Q?

If we recognize that each statement alone is not sufficient, we can jump straight to......

Statements 1 and 2 combined
There are several quadrilaterals satisfy BOTH statements. Here are two:
Case a: Q is a rectangle with width 1 and length 25. In this case, the perimeter of quadrilateral Q is 1 + 1 + 25 + 25 = 52
Case b: Q is a rectangle with width 5 and length 5. In this case, the perimeter of quadrilateral Q is 5 + 5 + 5 + 5 = 20
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Answer: E

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image