Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

It is currently 16 Jul 2019, 19:41

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

The sum of the ages of Lindsey and Meghan is y, and Lindsey is exactly

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 56244
The sum of the ages of Lindsey and Meghan is y, and Lindsey is exactly  [#permalink]

Show Tags

New post 13 Jun 2017, 05:58
00:00
A
B
C
D
E

Difficulty:

  85% (hard)

Question Stats:

50% (02:22) correct 50% (02:41) wrong based on 119 sessions

HideShow timer Statistics


SVP
SVP
User avatar
V
Joined: 26 Mar 2013
Posts: 2283
Reviews Badge CAT Tests
The sum of the ages of Lindsey and Meghan is y, and Lindsey is exactly  [#permalink]

Show Tags

New post 13 Jun 2017, 06:22
1
1
The sum of the ages of Lindsey and Meghan is y, and Lindsey is exactly 9 years older than Meghan. Natalie is how many years older than Meghan?

Let L: Lindsey's age, M:Meghan's age, N: Natalie's age.....All ages are in current time.

L + M = y.........1

L = M + 9.........2

From 1 in 2

2M + 9 = y.......3

N - M =????

(1) In y years, Meghan will be exactly three times as old as Natalie is now.

M + y = 3N.......4

From 3 in 4

M + 2M + 9 = 3N

3N - 3M = 9

N -M =3

Sufficient

(2) Lindsey is exactly 6 years older than Natalie.

L = N + 6......5

From 2 in 5

M + 9 = N + 6

N - M = 3

Sufficient

Answer: D
Senior PS Moderator
User avatar
V
Joined: 26 Feb 2016
Posts: 3360
Location: India
GPA: 3.12
Re: The sum of the ages of Lindsey and Meghan is y, and Lindsey is exactly  [#permalink]

Show Tags

New post 13 Jun 2017, 10:38
From the question stem,
Let Meghan's age be M, Lindsey's age be L and Natalie's age is N.
Given data
L + M = y
L - M = 9 => L = M + 9 and M = L - 9
From this we can deduce(adding both equations)
2L = y+9 or y = 2L - 9

We need to find N-M to find out how much older is Natalie when compared to Meghan

1.From statement 1, we get M + y = 3N
M + 2L - 9 = 3N
Substituting value of L from the question stem,
M + 2(M+9) - 9 = 3N
3N - 3M =9 => N-M = 3. Hence sufficient

2.From statement 2, we get L - N = 6
M + 9 - N = 6(since L = M + 9)
N - M = 3. Hence, sufficient(Option d)
_________________
You've got what it takes, but it will take everything you've got
SVP
SVP
User avatar
V
Joined: 26 Mar 2013
Posts: 2283
Reviews Badge CAT Tests
The sum of the ages of Lindsey and Meghan is y, and Lindsey is exactly  [#permalink]

Show Tags

New post 13 Jun 2017, 16:07
Another approach to the problem

The sum of the ages of Lindsey and Meghan is y, and Lindsey is exactly 9 years older than Meghan. Natalie is how many years older than Meghan?


Let L: Lindsey's age, M:Meghan's age, N: Natalie's age.....All ages are in current time.

Let M = 1 year

L = M + 9..........L = 10

y = L + M = 10 + 1 = 11

N - M =????

The question will be what is Natalie's age????

(1) In y years, Meghan will be exactly three times as old as Natalie is now.

M + y = 3N

1 +11 =3N..........N = 4

N -M =4 - 1 = 3

Sufficient

(2) Lindsey is exactly 6 years older than Natalie.

L = N + 6

10 = N +6

N= 4

N - M = 4 - 1= 3

Sufficient

Answer: D
Target Test Prep Representative
User avatar
G
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2823
Re: The sum of the ages of Lindsey and Meghan is y, and Lindsey is exactly  [#permalink]

Show Tags

New post 06 Jul 2017, 17:20
Bunuel wrote:
The sum of the ages of Lindsey and Meghan is y, and Lindsey is exactly 9 years older than Meghan. Natalie is how many years older than Meghan?

(1) In y years, Meghan will be exactly three times as old as Natalie is now.

(2) Lindsey is exactly 6 years older than Natalie.


We can let L = Lindsay’s current age, M = Meghan’s current age, and N = Natalie’s current age. Thus:

L + M = y

L = y - M

and

L = M + 9

Adding L = y - M and L = M + 9, we have:

2L = y + 9

y = 2L - 9

So, we now have the following equations:

L = y - M, L = M + 9, and y = 2L - 9.

We need to determine the value of N - M.

Statement One Alone:

In y years, Meghan will be exactly three times as old as Natalie is now.

Using the information in statement one, we can create the following equation:

M + y = 3N

Since y = 2L - 9, we have:

M + 2L - 9 = 3N

Since L = M + 9, we have:

M + 2(M + 9) - 9 = 3N

M + 2M + 18 - 9 = 3N

3M + 9 = 3N

3 = N - M

Statement one alone is sufficient to answer the question.

Statement Two Alone:

Lindsey is exactly 6 years older than Natalie.

We can create the following equation:

L = 6 + N

Since L = M + 9, we have:

M + 9 = 6 + N

N - M = 3

Statement two alone is sufficient to answer the question.

Answer: D
_________________

Jeffrey Miller

Head of GMAT Instruction

Jeff@TargetTestPrep.com
TTP - Target Test Prep Logo
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

Veritas Prep Representative
User avatar
S
Joined: 26 Jul 2010
Posts: 414
Re: The sum of the ages of Lindsey and Meghan is y, and Lindsey is exactly  [#permalink]

Show Tags

New post 06 Aug 2018, 08:36
Top Contributor
1
One thing I'd love to add to this one is a strategic note: if you look at the solutions here and in the Veritas Prep Practice Tests, the most common (and it's very common) mistake on this one is choosing B instead of D. So the mistake is "people don't realize that statement 1 is sufficient." And why not?

One of the easiest ways to trap people into picking a "less sufficient" answers is to ask for a combination of variables (instead of a specific variable itself). We're all really used to getting an equation and solving for x. But in most of our academic careers we rarely if ever solve directly for something like (2x - y) or, in this case, (N - M). For a lot of people, their natural inclination when they see:

Natalie is how many years older than Meghan?

Is to solve for Natalie's age, then solve for Meghan's age, then take the difference. But on Data Sufficiency, if the GMAT asks for a combination of variables (the difference between them, the sum of them, or something like that) it's almost always possible to solve for that combination with less information than it would take to solve for the variables individually, then combine. So when you see them ask for a combination, your instinct should be to "Leverage Assets" - really dig in to the algebra (as statement 1 requires here) to see if you can get directly to that combination. The fact that they asked that strange, overly-specific question is a clue that the right answer is probably "more sufficient" and the trap is "less sufficient," so perform your work accordingly.
_________________
Brian

Curriculum Developer, Instructor, and Host of Veritas Prep On Demand

Save $100 on live Veritas Prep GMAT Courses and Admissions Consulting

Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews
GMAT Club Bot
Re: The sum of the ages of Lindsey and Meghan is y, and Lindsey is exactly   [#permalink] 06 Aug 2018, 08:36
Display posts from previous: Sort by

The sum of the ages of Lindsey and Meghan is y, and Lindsey is exactly

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne