Events & Promotions
|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Apr 2512:30 AM EDT
-01:30 AM EDT
At one point, she believed GMAT wasn’t for her. After scoring 595, self-doubt crept in and she questioned her potential. But instead of quitting, she made the right strategic changes. The result? A remarkable comeback to 695. Check out how Saakshi did it.
Apr 2601:30 AM EDT
-02:30 AM EDT
Learn how Keshav, a Chartered Accountant, scored an impressive 705 on GMAT in just 30 days with GMATWhiz's expert guidance. In this video, he shares preparation tips and strategies that worked for him, including the mock, time management, and more.
Apr 2610:00 AM EDT
-11:00 AM EDT
The Target Test Prep course represents a quantum leap forward in GMAT preparation, a radical reinterpretation of the way that students should study. Try before you buy with a 5-day, full-access trial of the course for FREE!
Apr 2711:00 AM EDT
-12:00 PM EDT
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors
Apr 2808:00 AM PDT
-11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.
May 0111:00 AM PDT
-12:00 PM PDT
Free- full-length test + 15 concept videos + 150+ short videos + study plan!
07 Jun 2021, 06:45
Kudos
Bookmarks
E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
35%
(medium)
Question Stats:
67% (01:02) correct
33%
(01:24)
wrong
based on 27
sessions
History
Date
Time
Result
Not Attempted Yet
Which of the following cannot be an interior angle of a regular polygon (in degrees)?
A. 162
B. 150
C. 144
D. 140
E. 125
A. 162
B. 150
C. 144
D. 140
E. 125
07 Jun 2021, 09:03
Kudos
Bookmarks
If you know that in a regular hexagon, each angle is 120 degrees, answer E here should probably look suspicious immediately. If you also know that in a regular octagon, each angle is 135 degrees, and if you know that angles get bigger the more sides you have in a regular polygon, the only way 125 could be the angle in a regular polygon is if it were the size of an angle in a regular 7-sided shape. But if we sum the angles in any polygon, we get a multiple of 180, because every polygon can be divided up into triangles, and 7*125 isn't even an even number, so it certainly is not a multiple of 180, and it can't be the size of the angle in a regular 7-sided shape.
You could also do the problem algebraically - there might be a slightly more efficient way than this, but this works:
The sum of the angles in any n-sided polygon is (n-2)*180. In a regular n-sided polygon, those angles are all the same, so each angle is equal to
(n-2)*180/n = 180n/n - 360/n = 180 - (360/n)
Now we can see what's going on if we set this equal to one answer choice, say A:
180 - 360/n = 162
360/n = 180 - 162
and this has a solution, because when we subtract 162 from 180, we get 18, which is a factor of 360 (so it can equal 360/n where n is an integer). If an answer here will be impossible, it will be true that we do *not* get a factor of 360 when we subtract it from 180. Answers B, C and D give us 30, 36 and 40 when we subtract them from 180, all of which are factors of 360, but answer E gives us 55, which is clearly not a factor of 360 (since it's divisible by 11 but 360 is not), so 125 degrees cannot be the measure of an angle inside a regular polygon.
Posted from my mobile device
You could also do the problem algebraically - there might be a slightly more efficient way than this, but this works:
The sum of the angles in any n-sided polygon is (n-2)*180. In a regular n-sided polygon, those angles are all the same, so each angle is equal to
(n-2)*180/n = 180n/n - 360/n = 180 - (360/n)
Now we can see what's going on if we set this equal to one answer choice, say A:
180 - 360/n = 162
360/n = 180 - 162
and this has a solution, because when we subtract 162 from 180, we get 18, which is a factor of 360 (so it can equal 360/n where n is an integer). If an answer here will be impossible, it will be true that we do *not* get a factor of 360 when we subtract it from 180. Answers B, C and D give us 30, 36 and 40 when we subtract them from 180, all of which are factors of 360, but answer E gives us 55, which is clearly not a factor of 360 (since it's divisible by 11 but 360 is not), so 125 degrees cannot be the measure of an angle inside a regular polygon.
Posted from my mobile device
Archit3110
07 Jun 2021, 09:14
Kudos
Bookmarks
alternate way to solve
each interior angle = 180- 360/n
factors of 360 ; 2^3*3^2*5
360 = n * ( 180- ( answer option) )
only option E is not valid
each interior angle = 180- 360/n
factors of 360 ; 2^3*3^2*5
360 = n * ( 180- ( answer option) )
only option E is not valid
Bunuel
