GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 18 Oct 2018, 05:10

### 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

# Is n= 2m+ 3?

Author Message
TAGS:

### Hide Tags

Manager
Joined: 25 Sep 2018
Posts: 76
Location: United States (CA)
Concentration: Finance, Strategy
GMAT 1: 640 Q47 V30
GPA: 3.97
WE: Investment Banking (Investment Banking)

### Show Tags

28 Sep 2018, 11:31
1
00:00

Difficulty:

95% (hard)

Question Stats:

31% (01:34) correct 69% (01:49) wrong based on 75 sessions

### HideShow timer Statistics

Is $$n= 2m+ 3$$ ?

1)$$(n-3)^2$$ = $$4m^2$$
2)$$n^2$$ =$$4m^2 +12m+9$$

_________________

Why do we fall?...So we can learn to pick ourselves up again

If you like the post, give it a KUDOS!

Senior Manager
Joined: 18 Jul 2018
Posts: 271
Location: India
Concentration: Finance, Marketing
WE: Engineering (Energy and Utilities)
Re: Is n= 2m+ 3?  [#permalink]

### Show Tags

28 Sep 2018, 13:37
From statement 1:

$$(n−3)^2$$ = 4$$m^2$$

$$n^2$$+9-6n = 4$$m^2$$

Rearranging gives $$n^2$$ = 4$$m^2$$+6n-9.
A is insufficient.

From statement 2:

$$n^2$$ = 4$$m^2$$+12m+9

or $$n^2$$ = $$(2m+3)^2$$.

n can be +(2m+3) or -(2m+3).
Hence B is insufficient.

Combining both gives
4$$m^2$$+12m+9 = 4$$m^2$$+6n-9

or 12m-6n+18 = 0
2m-n+3 = 0
or n = 2m+3.

_________________

When you want something, the whole universe conspires in helping you achieve it.

Intern
Joined: 08 May 2016
Posts: 3
Re: Is n= 2m+ 3?  [#permalink]

### Show Tags

01 Oct 2018, 09:17
1
Please explain why C? I chose D.
(n-3)^2 = 4m^2
Moving RHS to LHS and using a^2 -b^2 = (a+b)(a-b)
We get
N-3-2m =0 and n- 3+2m =0
Therefore
N=2m+3 and 3-2m
Therefore the question is statistfied.

Similarly for statement B.

Manager
Joined: 25 Sep 2018
Posts: 76
Location: United States (CA)
Concentration: Finance, Strategy
GMAT 1: 640 Q47 V30
GPA: 3.97
WE: Investment Banking (Investment Banking)
Re: Is n= 2m+ 3?  [#permalink]

### Show Tags

01 Oct 2018, 09:36
You yourself have mentioned in the solution that there are 2 values one is positive and other is negative. If i a statement is giving two possible answers, it's clearly not sufficient.
_________________

Why do we fall?...So we can learn to pick ourselves up again

If you like the post, give it a KUDOS!

Intern
Joined: 08 May 2016
Posts: 3
Re: Is n= 2m+ 3?  [#permalink]

### Show Tags

01 Oct 2018, 10:06
Abhi077 wrote:
You yourself have mentioned in the solution that there are 2 values one is positive and other is negative. If i a statement is giving two possible answers, it's clearly not sufficient.

The question asks if n = 2m +3. The solution states that n can hold this value. The question never states that n should only have this value.
Senior Manager
Joined: 31 Jul 2017
Posts: 477
Location: Malaysia
GMAT 1: 700 Q50 V33
GPA: 3.95
WE: Consulting (Energy and Utilities)
Re: Is n= 2m+ 3?  [#permalink]

### Show Tags

01 Oct 2018, 10:29
Abhi077 wrote:
Is $$n= 2m+ 3$$ ?

1)$$(n-3)^2$$ = $$4m^2$$
2)$$n^2$$ =$$4m^2 +12m+9$$

Statement I;

Take m = 0, n = 3.

Take m = -1, n = 1,5.... Insufficient.

Statement II:

Take m = 0, n = 3,-3... Insufficient.

Combining the two Statements,

n = 2m + 3.
_________________

If my Post helps you in Gaining Knowledge, Help me with KUDOS.. !!

CEO
Joined: 12 Sep 2015
Posts: 3009
Re: Is n= 2m+ 3?  [#permalink]

### Show Tags

01 Oct 2018, 10:29
Top Contributor
Bhumsa wrote:
Please explain why C? I chose D.
(n-3)^2 = 4m^2
Moving RHS to LHS and using a^2 -b^2 = (a+b)(a-b)
We get
N-3-2m =0 and n- 3+2m =0
Therefore
N=2m+3 and N = 3-2m
Therefore the question is statistfied.

Similarly for statement B.

You're correct to say that statement 1 yields 2 possible solutions (in red above)
However, if N = 2m + 3, then the answer to the target question is "YES, n does equal 2m + 3)
And if N = 3 - 2m , then the answer to the target question is "NO, n does not equal 2m + 3)

Since we have 2 DIFFERENT answers to the target question, the statement is NOT sufficient.
_________________

Brent Hanneson – GMATPrepNow.com

Intern
Joined: 21 Oct 2012
Posts: 4
GMAT Date: 02-03-2016
Re: Is n= 2m+ 3?  [#permalink]

### Show Tags

09 Oct 2018, 07:50
n = 2m + 3 <=> n - 3 = 2m

1) --> |n-3| = |4m| --> insufficient
2) --> |n| = |2m + 3| --> insufficient

1-2) --> (n-3)^2 - n^2 = (4m)^2 - (2m+3) ^2
<=> n = 2m + 3

--> sufficient --> C
Re: Is n= 2m+ 3? &nbs [#permalink] 09 Oct 2018, 07:50
Display posts from previous: Sort by