Square roots of two successive positive integers, each greater than n^2 (n ≠0), differ by m, then m is less than
(A) 1/ (2 n)
(B) 1/n
(C) 2/n
(D) 3/n
(E) 4/n
m is less than
This topic has expert replies
- sanju09
- GMAT Instructor
- Posts: 3650
- Joined: Wed Jan 21, 2009 4:27 am
- Location: India
- Thanked: 267 times
- Followed by:80 members
- GMAT Score:760
The mind is everything. What you think you become. -Lord Buddha
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com
- ajith
- Legendary Member
- Posts: 1275
- Joined: Thu Sep 21, 2006 11:13 pm
- Location: Arabian Sea
- Thanked: 125 times
- Followed by:2 members
let the successive integers be k and k +1sanju09 wrote:Square roots of two successive positive integers, each greater than n^2 (n ≠0), differ by m, then m is less than
(A) 1/ (2 n)
(B) 1/n
(C) 2/n
(D) 3/n
(E) 4/n
sqrt(k) >n
m = sqrt(k+1) - sqrt(k)
=(sqrt(k+1) - sqrt(k))*(sqrt(k) + sqrt(k+1))/(sqrt(k) + sqrt(k+1))
= 1/(sqrt(k) + sqrt(k+1))
<1/(n+n)
<1/2n
[spoiler]A
[/spoiler]
Last edited by ajith on Mon Feb 22, 2010 4:25 am, edited 5 times in total.
Always borrow money from a pessimist, he doesn't expect to be paid back.
- sanju09
- GMAT Instructor
- Posts: 3650
- Joined: Wed Jan 21, 2009 4:27 am
- Location: India
- Thanked: 267 times
- Followed by:80 members
- GMAT Score:760
Won't the item in bold be zero?ajith wrote:let the successive integers be m and m+1sanju09 wrote:Square roots of two successive positive integers, each greater than n^2 (n ≠0), differ by m, then m is less than
(A) 1/ (2 n)
(B) 1/n
(C) 2/n
(D) 3/n
(E) 4/n
sqrt(m) >n
sqrt(m+1) - sqrt(m+1)
=(sqrt(m+1) - sqrt(m+1))*(sqrt(m+1) - sqrt(m+1))/(sqrt(m+1) + sqrt(m+1))
= 1/(sqrt(m+1) + sqrt(m+1))
<1/(n+n)
<1/2n
[spoiler]A
[/spoiler]
The mind is everything. What you think you become. -Lord Buddha
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com
- ajith
- Legendary Member
- Posts: 1275
- Joined: Thu Sep 21, 2006 11:13 pm
- Location: Arabian Sea
- Thanked: 125 times
- Followed by:2 members
Copy paste errors - Fixed in the original post, thanks for pointing out, you know that logic was right!sanju09 wrote:
Won't the item in bold be zero?
Always borrow money from a pessimist, he doesn't expect to be paid back.
- sanju09
- GMAT Instructor
- Posts: 3650
- Joined: Wed Jan 21, 2009 4:27 am
- Location: India
- Thanked: 267 times
- Followed by:80 members
- GMAT Score:760
Characters changed yet character remains!ajith wrote:let the successive integers be k and k +1sanju09 wrote:Square roots of two successive positive integers, each greater than n^2 (n ≠0), differ by m, then m is less than
(A) 1/ (2 n)
(B) 1/n
(C) 2/n
(D) 3/n
(E) 4/n
sqrt(k) >n
m = sqrt(k+1) - sqrt(k)
=(sqrt(k+1) - sqrt(k))*(sqrt(k+1) + sqrt(k+1))/(sqrt(k+1) + sqrt(k+1))
= 1/(sqrt(k+1) + sqrt(k+1))
<1/(n+n)
<1/2n
[spoiler]A
[/spoiler]
The mind is everything. What you think you become. -Lord Buddha
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com
- ajith
- Legendary Member
- Posts: 1275
- Joined: Thu Sep 21, 2006 11:13 pm
- Location: Arabian Sea
- Thanked: 125 times
- Followed by:2 members
Edited again!sanju09 wrote: Characters changed yet character remains!
I am so happy that they have objective type questions in GMAT
Always borrow money from a pessimist, he doesn't expect to be paid back.
- sanju09
- GMAT Instructor
- Posts: 3650
- Joined: Wed Jan 21, 2009 4:27 am
- Location: India
- Thanked: 267 times
- Followed by:80 members
- GMAT Score:760
The titanic cost of pretty few things is never minded, HAPPINESS is one of theseajith wrote:Edited again!sanju09 wrote: Characters changed yet character remains!
I am so happy that they have objective type questions in GMAT
The mind is everything. What you think you become. -Lord Buddha
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com
- ajith
- Legendary Member
- Posts: 1275
- Joined: Thu Sep 21, 2006 11:13 pm
- Location: Arabian Sea
- Thanked: 125 times
- Followed by:2 members
Ahem! Let us not digress!sanju09 wrote: The titanic cost of pretty few things is never minded, HAPPINESS is one of these
Always borrow money from a pessimist, he doesn't expect to be paid back.