|
|
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.
12 May 2020, 13:27
Kudos
Bookmarks
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
55%
(hard)
Question Stats:
65% (02:00) correct
35%
(02:26)
wrong
based on 194
sessions
History
Date
Time
Result
Not Attempted Yet
For what positive integer n are \(\frac{6+4√n}{n}\) and \(\frac{6-4√n}{n} \)reciprocals?
(A) 1
(B) 2
(C) 4
(D) 6
(E) 8
(A) 1
(B) 2
(C) 4
(D) 6
(E) 8
12 May 2020, 17:54
Kudos
Bookmarks
For what positive integer n are 6+4√n/n and 6−4√n/n reciprocals?
6+4√n/n and 6−4√n/n are reciprocals
so,[6+4√n/n]* [6−4√n/n]=1
or,[36-16n]/n^2=1
or,n^2=36-16n
or,n^2+16n-36=0
or,(n+18)(n-2)=0
since,n must be positive to be √n validated , we can say n= 2
correct answer B
6+4√n/n and 6−4√n/n are reciprocals
so,[6+4√n/n]* [6−4√n/n]=1
or,[36-16n]/n^2=1
or,n^2=36-16n
or,n^2+16n-36=0
or,(n+18)(n-2)=0
since,n must be positive to be √n validated , we can say n= 2
correct answer B
