It is currently 22 Sep 2017, 06:48

### 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 June
Open Detailed Calendar

# There are three consecutive #s such that the square of the

Author Message
Senior Manager
Joined: 30 Aug 2003
Posts: 329

Kudos [?]: 25 [0], given: 0

Location: BACARDIVILLE
There are three consecutive #s such that the square of the [#permalink]

### Show Tags

03 Mar 2004, 17:31
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

There are three consecutive #s such that the square of the middle # exceeds the difference of the squares of the first and last #s by 60. What is the last of the three #s?

10
14
11
17

_________________

Pls include reasoning along with all answer posts.
****GMAT Loco****
Este examen me conduce jodiendo loco

Kudos [?]: 25 [0], given: 0

Director
Joined: 03 Jul 2003
Posts: 651

Kudos [?]: 101 [0], given: 0

### Show Tags

03 Mar 2004, 17:37
Ans: 11

Let the numbers be a, a+1 and a+2

(a+1)^2 = 60 + [(a+2)^2 - a^2]

Solve for "a"

Kudos [?]: 101 [0], given: 0

Manager
Joined: 11 Oct 2003
Posts: 102

Kudos [?]: [0], given: 0

Location: USA

### Show Tags

03 Mar 2004, 18:03

I think if you tried a-1, a and a+1 your calulations will be much easier..

Kudos [?]: [0], given: 0

Director
Joined: 03 Jul 2003
Posts: 651

Kudos [?]: 101 [0], given: 0

### Show Tags

03 Mar 2004, 19:48
mantha wrote:

I think if you tried a-1, a and a+1 your calulations will be much easier..

Mantha:

Thank you for the tip.
This is the power of collaborative learning!

Last edited by kpadma on 04 Mar 2004, 05:39, edited 1 time in total.

Kudos [?]: 101 [0], given: 0

Director
Joined: 13 Nov 2003
Posts: 789

Kudos [?]: 59 [0], given: 0

Location: BULGARIA

### Show Tags

04 Mar 2004, 01:58
Kpadma, please note that the question is about the DIFFERENCE BETWEEN THE FIRST AND THE LAST NUMBER not the other way round.If you try the values that you have suggested you 'll see that 9,10,11 9^2-11^2=-40 so the square of the middle number exceeds the difference by 140, not 60. IMO, the numbers are -11,-10,-9 so the answer should be E)

Kudos [?]: 59 [0], given: 0

Manager
Joined: 25 Apr 2003
Posts: 227

Kudos [?]: 162 [0], given: 0

### Show Tags

04 Mar 2004, 03:49
why is mantha's method (yielding 10 and -6 as solutions and thereby a+1 becomes 11 as answer ) not correct ? I didn't understand.

Kudos [?]: 162 [0], given: 0

Director
Joined: 03 Jul 2003
Posts: 651

Kudos [?]: 101 [0], given: 0

### Show Tags

04 Mar 2004, 05:51
BG wrote:
Kpadma, please note that the question is about the DIFFERENCE BETWEEN THE FIRST AND THE LAST NUMBER not the other way round.

Yes, you've a point. I've also noticed that issue, when I solved the problem.

But, Is it not true that the difference between two number is always postive
or zero. For exampble, "difference between A and B" is | A - B |, whereas
"A exceeds B" is A - B.

I could be wrong, so it is worth clearing up this confusion.

Dear Praetorian or Akamai,
Could you help us with this issue?

Kudos [?]: 101 [0], given: 0

04 Mar 2004, 05:51
Display posts from previous: Sort by