Find all School-related info fast with the new School-Specific MBA Forum

It is currently 22 Jul 2014, 22:26

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Ms. Morris invested in Fund A and Fund B. The total amount

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Expert Post
Magoosh GMAT Instructor
User avatar
Joined: 28 Dec 2011
Posts: 1932
Followers: 465

Kudos [?]: 1837 [0], given: 29

Ms. Morris invested in Fund A and Fund B. The total amount [#permalink] New post 26 Oct 2012, 13:02
Expert's post
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

69% (03:29) correct 31% (02:40) wrong based on 99 sessions
Ms. Morris invested in Fund A and Fund B. The total amount she invested, in both funds combined, was $100,000. In one year, Fund A paid 23% and Fund B paid 17%. The interest earned in Fund B was exactly $200 greater than the interest earned in Fund A. How much did Ms. Morris invest in Fund A?
(A) $32,000
(B) $36,000
(C) $40,000
(D) $42,000
(E) $45,000


For this question, one could do an algebraic solution, but would it be faster to backsolve from the answers? I would argue for the latter, though I imagine there will be a difference of opinions on this question.

My argument, along with a discussion of backsolving in general and a complete solution to this problem, is here:
http://magoosh.com/gmat/2012/gmat-plugg ... -choice-c/

Perhaps other experts would also like to chime in on the issue of when to solve algebraically vs. when to backsolve.

Mike :-)
[Reveal] Spoiler: OA

_________________

Mike McGarry
Magoosh Test Prep

Image

Image


Last edited by mikemcgarry on 26 Oct 2012, 15:28, edited 1 time in total.
Kaplan GMAT Prep Discount CodesKnewton GMAT Discount CodesGMAT Pill GMAT Discount Codes
1 KUDOS received
Director
Director
User avatar
Joined: 22 Mar 2011
Posts: 613
WE: Science (Education)
Followers: 65

Kudos [?]: 474 [1] , given: 43

GMAT Tests User
Re: backsolving [#permalink] New post 26 Oct 2012, 14:42
1
This post received
KUDOS
mikemcgarry wrote:
Ms. Morris invested in Fund A and Fund B. The total amount she invested, in both funds combined, was $100,000. In one year, Fund A paid 23% and Fund B paid 17%. The interest earned in Fund B was exactly $200 greater than the interest earned in Fund A. How much did Ms. Morris invest in Fund A?
(A) $32,000
(B) $36,000
(C) $40,000
(D) $44,000
(E) $45,000


For this question, one could do an algebraic solution, but would it be faster to backsolve from the answers? I would argue for the latter, though I imagine there will be a difference of opinions on this question.

My argument, along with a discussion of backsolving in general and a complete solution to this problem, is here:
http://magoosh.com/gmat/2012/gmat-plugg ... -choice-c/

Perhaps other experts would also like to chime in on the issue of when to solve algebraically vs. when to backsolve.

Mike :-)



The correct answer should be 42,000, and it is not listed neither above, nor in the question you published on your blog.
It just appears in the solution you posted.

_________________

PhD in Applied Mathematics
Love GMAT Quant questions and running.

Expert Post
Magoosh GMAT Instructor
User avatar
Joined: 28 Dec 2011
Posts: 1932
Followers: 465

Kudos [?]: 1837 [0], given: 29

Re: backsolving [#permalink] New post 26 Oct 2012, 15:30
Expert's post
EvaJager wrote:
The correct answer should be 42,000, and it is not listed neither above, nor in the question you published on your blog.
It just appears in the solution you posted.

Yes, you're right --- a mistake on my part --- the OA is $42,000, and I just corrected the question above & the blog. Thank you very much.

Mike :-)

_________________

Mike McGarry
Magoosh Test Prep

Image

Image

Intern
Intern
avatar
Joined: 18 May 2012
Posts: 15
Followers: 0

Kudos [?]: 0 [0], given: 1

Re: Ms. Morris invested in Fund A and Fund B. The total amount [#permalink] New post 16 Nov 2012, 12:07
Could someone post the algebraic way please
Manager
Manager
avatar
Joined: 05 Nov 2012
Posts: 147
Followers: 1

Kudos [?]: 5 [0], given: 56

Re: Ms. Morris invested in Fund A and Fund B. The total amount [#permalink] New post 16 Nov 2012, 13:07
chibimoon wrote:
Could someone post the algebraic way please

A+B=100k
0.17B=0.23A+200=> -23A+17B=20000

from first equation 23A+23B=2300K
add above and eq2
40B=2320K
B=58K

A=100k-58k=42k
1 KUDOS received
Intern
Intern
User avatar
Affiliations: SAG-AFTRA, AEA
Joined: 27 May 2011
Posts: 15
Location: United States
Concentration: Technology, Strategy
GMAT Date: 04-20-2013
WE: Performing Arts (Entertainment and Sports)
Followers: 0

Kudos [?]: 8 [1] , given: 20

GMAT ToolKit User
Re: Ms. Morris invested in Fund A and Fund B. The total amount [#permalink] New post 02 Feb 2013, 15:35
1
This post received
KUDOS
chibimoon wrote:
Could someone post the algebraic way please


A+B=100,000

0.17B=0.23A+200

You now have two equations, so you can either substitute or eliminate. In the explanation above, elimination is used, here I use substitution (elimination is easier in this case)

Take away decimals first: 17B=23A+20,000

Isolate first equation to solve for A (your goal): B=100,000-A

Plug in for B:
17(100,000-A)=23A+20,000
1,700,000-17A=23A+20,000
1,680,000=40A
1,680,000/40=A
A=42,000=Answer Choice D

_________________

"How far that little candle throws his beams.
So shines a good deed in a weary world."
- Shakespeare

Expert Post
Magoosh GMAT Instructor
User avatar
Joined: 28 Dec 2011
Posts: 1932
Followers: 465

Kudos [?]: 1837 [0], given: 29

Re: Ms. Morris invested in Fund A and Fund B. The total amount [#permalink] New post 02 May 2013, 10:29
Expert's post
Here's another problem from that same article, one that's even less amenable to algebraic treatment.

If the sequence a(n) is defined as a(n) = n^2 + n + \sqrt{n+3}, then which of the following values of n represents the first terms such that a(n) > 500?
(A) 13
(B) 22
(C) 33
(D) 46
(E) 78


[Reveal] Spoiler:
OA = (B)


A full solution is shown at that that article:
http://magoosh.com/gmat/2012/gmat-plugg ... -choice-c/

Mike :-)

_________________

Mike McGarry
Magoosh Test Prep

Image

Image

Re: Ms. Morris invested in Fund A and Fund B. The total amount   [#permalink] 02 May 2013, 10:29
    Similar topics Author Replies Last post
Similar
Topics:
Sustainable/SRI Investment Funds bschoolq2 0 12 May 2012, 17:18
Funding deckardbr 1 14 May 2008, 09:48
What's the amount of the fund nick_sun 2 09 Jul 2007, 04:02
The city government should invest surplus funds in improving ps_dahiya 13 16 Jul 2006, 19:14
An investment broker handles 600 investment funds, 70% of kevincan 1 08 Jul 2006, 05:35
Display posts from previous: Sort by

Ms. Morris invested in Fund A and Fund B. The total amount

  Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.