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 2912:30 AM EDT
-01:30 AM EDT
Learn how Kamakshi achieved a GMAT 675 with an impressive 96th %ile in Data Insights. Discover the unique methods and exam strategies that helped her excel in DI along with other sections for a balanced and high score.
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.
Apr 3001:30 AM EDT
-02:30 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.
May 0111:00 AM PDT
-12:00 PM PDT
Free- full-length test + 15 concept videos + 150+ short videos + study plan!
May 0306:30 AM PDT
-08:30 AM PDT
Verbal trouble on GMAT? Fix it NOW! Join Sunita Singhvi for a focused webinar on actionable strategies to boost your Verbal score and take your performance to the next level.
03 Mar 2021, 03:30
Kudos
Bookmarks
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
65%
(hard)
Question Stats:
59% (02:49) correct
41%
(02:27)
wrong
based on 118
sessions
History
Date
Time
Result
Not Attempted Yet
The number of arrangements of 2n+2 different objects taken n at a time is to the number of arrangements of 2n different objects taken n at a time as 14:5. What is the value of n?
A. 2
B. 3
C. 4
D. 5
E. 6
Are You Up For the Challenge: 700 Level Questions: 700 Level Questions
A. 2
B. 3
C. 4
D. 5
E. 6
Are You Up For the Challenge: 700 Level Questions: 700 Level Questions
03 Mar 2021, 04:26
Kudos
Bookmarks
\(\frac{^{2n + 2}P_n}{^{2n}P_n} = \frac{14}{5}\)
\(\frac{\frac{(2n + 2)!}{(2n + 2 - n)!}}{\frac{(2n)!}{(2n - n)!}} = \frac{14}{5}\)
\(\frac{\frac{(2n + 2)!}{(n + 2)!}}{\frac{(2n)!}{(n)!}} = \frac{14}{5}\)
\(\frac{(2n + 2)! * n!}{(n + 2)! * (2n)!} = \frac{14}{5}\)
\(\frac{(2n + 2)(2n + 1)(2n)! * n!}{(n + 2)(n + 1)n! * (2n)!} = \frac{14}{5}\)
\(\frac{(2n + 2)(2n + 1)}{(n + 2)(n + 1)} = \frac{14}{5}\)
\(5(4n^2 + 6n + 2) = 14(n^2 + 3n + 2)\)
\(20n^2 + 30n + 10 = 14n^2 + 42n + 28\)
\(6n^2 - 12n - 18 = 0\)
\(n^2 - n - 3 = 0\)
\(n^2 - 3n + n - 3 = 0\)
n(n -3) + 1(n - 3) = 0
(n + 1)(n - 3) = 0
n = -1 (Not possible) or n = 3
Option B
Arun Kumar
\(\frac{\frac{(2n + 2)!}{(2n + 2 - n)!}}{\frac{(2n)!}{(2n - n)!}} = \frac{14}{5}\)
\(\frac{\frac{(2n + 2)!}{(n + 2)!}}{\frac{(2n)!}{(n)!}} = \frac{14}{5}\)
\(\frac{(2n + 2)! * n!}{(n + 2)! * (2n)!} = \frac{14}{5}\)
\(\frac{(2n + 2)(2n + 1)(2n)! * n!}{(n + 2)(n + 1)n! * (2n)!} = \frac{14}{5}\)
\(\frac{(2n + 2)(2n + 1)}{(n + 2)(n + 1)} = \frac{14}{5}\)
\(5(4n^2 + 6n + 2) = 14(n^2 + 3n + 2)\)
\(20n^2 + 30n + 10 = 14n^2 + 42n + 28\)
\(6n^2 - 12n - 18 = 0\)
\(n^2 - n - 3 = 0\)
\(n^2 - 3n + n - 3 = 0\)
n(n -3) + 1(n - 3) = 0
(n + 1)(n - 3) = 0
n = -1 (Not possible) or n = 3
Option B
Arun Kumar
03 Mar 2021, 12:15
Kudos
Bookmarks
CrackVerbalGMAT
Though I got the right answer, I did it by Using a combination formula rather than a permutation one.
Can you please explain the question slightly in detail?
Though I got the right answer, I did it by Using a combination formula rather than a permutation one.
Can you please explain the question slightly in detail?
