GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 13 Dec 2018, 22:12

### 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 December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
• ### GMATbuster's Weekly GMAT Quant Quiz, Tomorrow, Saturday at 9 AM PST

December 14, 2018

December 14, 2018

09:00 AM PST

10:00 AM PST

10 Questions will be posted on the forum and we will post a reply in this Topic with a link to each question. There are prizes for the winners.
• ### Typical Day of a UCLA MBA Student - Recording of Webinar with UCLA Adcom and Student

December 14, 2018

December 14, 2018

10:00 PM PST

11:00 PM PST

Carolyn and Brett - nicely explained what is the typical day of a UCLA student. I am posting below recording of the webinar for those who could't attend this session.

# How many sides does polygon P have? (1) All sides of P have equal len

Author Message
TAGS:

### Hide Tags

Manager
Joined: 13 Sep 2016
Posts: 120
How many sides does polygon P have? (1) All sides of P have equal len  [#permalink]

### Show Tags

18 May 2018, 04:13
4
00:00

Difficulty:

15% (low)

Question Stats:

73% (00:37) correct 27% (00:26) wrong based on 92 sessions

### HideShow timer Statistics

How many sides does polygon P have?

(1) All sides of P have equal lengths.

(2) The sum of the measures of the interior angles of P is $$1,440^{\circ}$$
Manager
Joined: 03 Oct 2016
Posts: 127
How many sides does polygon P have? (1) All sides of P have equal len  [#permalink]

### Show Tags

18 May 2018, 04:35
1
alanforde800Maximus wrote:
How many sides does polygon P have?

(1) All sides of P have equal lengths. - Clearly Not Sufficient.

(2) The sum of the measures of the interior angles of P is $$1,440^{\circ}$$ - Sufficient.

Sum of Interior angles of a polygon = $$(n-2)$$ * $$180^{\circ}$$=$$1440^{\circ}$$ $$-> n=10.$$

As its a DS question so, if we know the formula, we know that B will be sufficient. We don't have to do the entire calculation.

_________________

Non-Allergic To Kudos

CEO
Joined: 11 Sep 2015
Posts: 3237
Re: How many sides does polygon P have? (1) All sides of P have equal len  [#permalink]

### Show Tags

18 May 2018, 08:24
2
Top Contributor
alanforde800Maximus wrote:
How many sides does polygon P have?

(1) All sides of P have equal lengths.

(2) The sum of the measures of the interior angles of P is $$1,440^{\circ}$$

Target question: How many sides does polygon P have?

Statement 1: All sides of P have equal lengths.
There are infinitely many polygons that satisfy statement 1. Here are two:
Case a: Polygon P is an equilateral triangle. In this case, the answer to the target question is polygon P has 3 sides
Case b: Polygon P is a square. In this case, the answer to the target question is polygon P has 4 sides
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: The sum of the measures of the interior angles of P is 1440º
Useful rule: the sum of the angles in an n-sided polygon = (n - 2)(180º)
So, we can write the equation: (n - 2)(180º) = 1440º
STOP: We need not solve this equation for n.
We need only recognize that we COULD solve it for n (but we won't, because that would be a waste of valuable time)
Since we COULD answer the target question with certainty, statement 2 is SUFFICIENT

Cheers,
Brent
_________________

Test confidently with gmatprepnow.com

Intern
Joined: 07 Dec 2017
Posts: 17
Re: How many sides does polygon P have? (1) All sides of P have equal len  [#permalink]

### Show Tags

18 May 2018, 08:40
the sum of the angles in an n-sided polygon = (n - 2)(180º)
Intern
Joined: 04 Jul 2018
Posts: 1
How many sides does polygon P have? (1) All sides of P have equal len  [#permalink]

### Show Tags

07 Jul 2018, 10:37
For those wondering whether it matters if the polygon is regular or irregular, in this question it does not:

The sum of the interior angles of an n-sided polygon is always = (n-2) * 180

The sum of each of the angles is [(n-2) * 180]/n, if the polygon is regular.

Here they are just asking for the number of sides ('n'), not each of the interior angles of polygon.
How many sides does polygon P have? (1) All sides of P have equal len &nbs [#permalink] 07 Jul 2018, 10:37
Display posts from previous: Sort by