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

 It is currently 05 May 2015, 04:41

### 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

# All, this Q has been discussed many times. I'm interested in

Author Message
TAGS:
Manager
Joined: 26 Jun 2007
Posts: 107
Followers: 2

Kudos [?]: 32 [0], given: 0

All, this Q has been discussed many times. I'm interested in [#permalink]  24 Mar 2008, 01:00
All, this Q has been discussed many times. I'm interested in plugging numbers approach since solving this Q can result in arithmetic errors. Any takers?
This year Henry will save a certain amount of his income, and he will spend the rest. Next year Henry will have no income, but for each dollar that he saves this year, he will have 1 + r dollars available to spend. In terms of r, what fraction of his income should Henry save this year so that next year the amount he was available to spend will be equal to half the amount that he spends this year?

A. 1/(r+2)
B. 1/(2r+2)
C. 1/(3r+2)
D. 1/(r+3)
E. 1/(2r+3)
Manager
Joined: 20 Aug 2007
Posts: 65
Followers: 1

Kudos [?]: 9 [0], given: 0

Re: set27 Q19 - Henry [#permalink]  24 Mar 2008, 02:02
GGUY wrote:
All, this Q has been discussed many times. I'm interested in plugging numbers approach since solving this Q can result in arithmetic errors. Any takers?
This year Henry will save a certain amount of his income, and he will spend the rest. Next year Henry will have no income, but for each dollar that he saves this year, he will have 1 + r dollars available to spend. In terms of r, what fraction of his income should Henry save this year so that next year the amount he was available to spend will be equal to half the amount that he spends this year?

A. 1/(r+2)
B. 1/(2r+2)
C. 1/(3r+2)
D. 1/(r+3)
E. 1/(2r+3)

Well, in my opinion, it's not that hard to just solve in a direct way

Let T=total amount he earns in first year
A = proportion he saves (and this is what we wanna find)

Thus, amount he saves in first year = TA
amount he spends = T(1-A)
in second year, amount he saves will become TA(1+r)

we get equation TA(1+r) = T(1-A)/2
2TA(1+r) = T(1-A)
2A(1+r) = 1-A
2A+2Ar = 1-A
3A+2Ar = 1
A(3+2r) = 1
A = 1/(3+2r)
Senior Manager
Joined: 15 Aug 2007
Posts: 252
Schools: Chicago Booth
Followers: 1

Kudos [?]: 55 [0], given: 0

Re: set27 Q19 - Henry [#permalink]  24 Mar 2008, 06:02
prov wrote:
GGUY wrote:
All, this Q has been discussed many times. I'm interested in plugging numbers approach since solving this Q can result in arithmetic errors. Any takers?
This year Henry will save a certain amount of his income, and he will spend the rest. Next year Henry will have no income, but for each dollar that he saves this year, he will have 1 + r dollars available to spend. In terms of r, what fraction of his income should Henry save this year so that next year the amount he was available to spend will be equal to half the amount that he spends this year?

A. 1/(r+2)
B. 1/(2r+2)
C. 1/(3r+2)
D. 1/(r+3)
E. 1/(2r+3)

Well, in my opinion, it's not that hard to just solve in a direct way

Let T=total amount he earns in first year
A = proportion he saves (and this is what we wanna find)

Thus, amount he saves in first year = TA
amount he spends = T(1-A)
in second year, amount he saves will become TA(1+r)

we get equation TA(1+r) = T(1-A)/2
2TA(1+r) = T(1-A)
2A(1+r) = 1-A
2A+2Ar = 1-A
3A+2Ar = 1
A(3+2r) = 1
A = 1/(3+2r)

I echo what prov said... inafct chosing values will take longer because of the math involved with r and divisions. Solving it directly is not very hard and guess is the quickest way.
Manager
Joined: 27 Apr 2008
Posts: 111
Followers: 1

Kudos [?]: 8 [0], given: 0

Re: set27 Q19 - Henry [#permalink]  27 Sep 2008, 04:16
the equation is- (R-C)*(1+r)=C, where R=Revenue, C=consume, S= savings

=> (R-C)/C = 1/(1+r)

=> R/C = (2+r)/)1+r)

=> C/R = (1+r)/(2+r)

=> S/R = 1-C/R = 1-(1+r)/(2+r) = 1/(2+r)

thus A
Re: set27 Q19 - Henry   [#permalink] 27 Sep 2008, 04:16
Similar topics Replies Last post
Similar
Topics:
1 This one has already been discussed here: 1 17 Jul 2010, 13:00
1 This one has already been discussed here: 8 07 Jul 2010, 10:16
This one has alreadhy been discussed here: 8 04 Jul 2010, 09:56
This one has already been discussed here: 3 03 Jul 2010, 07:16
I know this one has been discussed many times, but I would 5 28 Apr 2007, 07:02
Display posts from previous: Sort by