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

It is currently 17 Feb 2019, 08:02

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
Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
  • Free GMAT Algebra Webinar

     February 17, 2019

     February 17, 2019

     07:00 AM PST

     09:00 AM PST

    Attend this Free Algebra Webinar and learn how to master Inequalities and Absolute Value problems on GMAT.
  • Valentine's day SALE is on! 25% off.

     February 18, 2019

     February 18, 2019

     10:00 PM PST

     11:00 PM PST

    We don’t care what your relationship status this year - we love you just the way you are. AND we want you to crush the GMAT!

The sum of Doris and Fred's ages is y . Doris is 12 years

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Intern
Intern
avatar
Joined: 16 Sep 2006
Posts: 22
The sum of Doris and Fred's ages is y . Doris is 12 years  [#permalink]

Show Tags

New post 16 Sep 2006, 19:02
The sum of Doris and Fred's ages is y. Doris is 12 years older than Fred. How many years old will Fred be y years from now, in terms of y.
A. y-6
b. 2y-6
C. y/2-6
D. 3y/2-6
E. 5y/2-6

I have the answer by plugging in numbers, but can't figure out how this formula came about. Any help would be greatly appreciated. Thanks.

--== Message from the GMAT Club Team ==--

THERE IS LIKELY A BETTER DISCUSSION OF THIS EXACT QUESTION.
This discussion does not meet community quality standards. It has been retired.


If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
Intern
Intern
User avatar
Joined: 23 Jul 2006
Posts: 48
  [#permalink]

Show Tags

New post 16 Sep 2006, 19:19
Hi.

You have:

D + F = Y

and you have that:

D = F + 12

If you replace the second equation in the first euation, we have:

2F + 12 = Y => F = (Y-12)/2

That is the Fred´s age today. In y more years will be: F + Y ==>

==> (Y-12)/2 + Y ==> (3/2)Y - 6 ..... (D)
_________________

Woody crack the GMAT

Intern
Intern
avatar
Joined: 16 Sep 2006
Posts: 22
  [#permalink]

Show Tags

New post 16 Sep 2006, 19:29
Thank you, I can sleep now...
Retired Moderator
User avatar
B
Joined: 05 Jul 2006
Posts: 1714
GMAT ToolKit User Premium Member
  [#permalink]

Show Tags

New post 17 Sep 2006, 01:56
The sum of Doris and Fred's ages is y. Doris is 12 years older than Fred. How many years old will Fred be y years from now, in terms of y.
A. y-6
b. 2y-6
C. y/2-6
D. 3y/2-6
E. 5y/2-6

D+F = Y BUT F+12 = D THUS 2F +12 = Y

F NOW = Y-12/2 , F Y YEARS FROM NOW = (Y-12)/2 +Y = 3y/2-6

my answer is D
Senior Manager
Senior Manager
avatar
Joined: 20 Feb 2006
Posts: 363
  [#permalink]

Show Tags

New post 17 Sep 2006, 03:05
D) 3y/2 - 6

Same working as above
Intern
Intern
avatar
Joined: 17 Apr 2006
Posts: 42
Re: Math Question driving me nuts!!! Please help  [#permalink]

Show Tags

New post 17 Sep 2006, 10:11
axl169 wrote:
The sum of Doris and Fred's ages is y. Doris is 12 years older than Fred. How many years old will Fred be y years from now, in terms of y.
A. y-6
b. 2y-6
C. y/2-6
D. 3y/2-6
E. 5y/2-6

I have the answer by plugging in numbers, but can't figure out how this formula came about. Any help would be greatly appreciated. Thanks.


Ans: D

Here'z how:

d + f = y, and d = f + 12, (d and f are ages of Doris and Fred)

therefore: 2f + 12 = y or f = (y-12)/2 --- (1)

Fred's age, y years from now is f + 12
= y/2 -6 + y
= 3y/2 - 6
Senior Manager
Senior Manager
User avatar
Joined: 28 Aug 2006
Posts: 296
Re: Math Question driving me nuts!!! Please help  [#permalink]

Show Tags

New post Updated on: 25 Sep 2008, 00:25
2
axl169 wrote:
The sum of Doris and Fred's ages is y. Doris is 12 years older than Fred. How many years old will Fred be y years from now, in terms of y.
A. y-6
b. 2y-6
C. y/2-6
D. 3y/2-6
E. 5y/2-6

I have the answer by plugging in numbers, but can't figure out how this formula came about. Any help would be greatly appreciated. Thanks.


Folks, again different ways were given to answer this.
But where is our faster method i.e giving some values and then proceeding...

Let F=24 Clearly D = 36, this mean y=60
After y years ie after 60 years F= 24+60 = 84.

Go to options.........
Placing y=60 Option D gives us 84.
So it is D.........

I recommend all of u to get into these methods

Regards,
_________________

Averages Accelerated:Guide to solve Averages Quickly(with 10 practice problems)


Originally posted by cicerone on 17 Sep 2006, 20:08.
Last edited by cicerone on 25 Sep 2008, 00:25, edited 1 time in total.
Director
Director
User avatar
Joined: 28 Dec 2005
Posts: 700
Re: Math Question driving me nuts!!! Please help  [#permalink]

Show Tags

New post 17 Sep 2006, 22:41
axl169 wrote:
The sum of Doris and Fred's ages is y. Doris is 12 years older than Fred. How many years old will Fred be y years from now, in terms of y.
A. y-6
b. 2y-6
C. y/2-6
D. 3y/2-6
E. 5y/2-6

I have the answer by plugging in numbers, but can't figure out how this formula came about. Any help would be greatly appreciated. Thanks.


d+f=y
d=f+2
=>2f+12=y
=>f = (y-12)/2
f+y = (y-12)/2+y = 3y/2 -6

D
Director
Director
avatar
Joined: 06 Sep 2006
Posts: 666
  [#permalink]

Show Tags

New post 19 Sep 2006, 11:43
1
1
D + F = Y; D = 12 + F; => 12 + F + F = Y => 2F = Y - 12

=> F = (Y - 12)/2

After Y years:
F = (Y - 12)/2 + Y => (Y -12 + 2Y)/2 => (3Y - 12)/2

=> 3Y/2 - 6. So D is my choice.
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 9836
Premium Member
Re: The sum of Doris and Fred's ages is y . Doris is 12 years  [#permalink]

Show Tags

New post 13 Oct 2018, 06:47
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

GMAT Club Bot
Re: The sum of Doris and Fred's ages is y . Doris is 12 years   [#permalink] 13 Oct 2018, 06:47
Display posts from previous: Sort by

The sum of Doris and Fred's ages is y . Doris is 12 years

  post reply Question banks Downloads My Bookmarks Reviews Important topics  

Moderators: chetan2u, Gladiator59



Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.