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

It is currently 27 Aug 2014, 21:12

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

If a farmer sells 15 of his chickens, his stock of feed will

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 05 Apr 2012
Posts: 43
Followers: 0

Kudos [?]: 8 [0], given: 12

If a farmer sells 15 of his chickens, his stock of feed will [#permalink] New post 01 May 2012, 13:53
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

67% (02:45) correct 33% (02:10) wrong based on 24 sessions
If a farmer sells 15 of his chickens, his stock of feed will last for 4 more days than planned, but if he buys 20 more chickens, he will run out of feed 3 days earlier than planned. If no chickens are sold or bought, the farmer will be exactly on schedule. How many chickens does the farmer have?

A. 12
B. 24
C. 48
D. 55
E. 60

My approach is as follow
the load be defined as the number of chicken x the number of day
let x be the number of chicken and D the number of day


case 1 (X-15) x (D+4)
case 2 (X+20)x (D+3)
from there I am stuck
please help !

best regards
[Reveal] Spoiler: OA
Intern
Intern
avatar
Joined: 22 Jan 2012
Posts: 35
Followers: 0

Kudos [?]: 12 [0], given: 0

GMAT Tests User
Re: If a farmer sells 15 of his chickens, his stock of feed will [#permalink] New post 01 May 2012, 15:59
Let x = total feed required for the planned period

n= number of chicken
t = total time of the planned feed

x = nt

1) x = (n-15) * (t+4)

2) x = (n+20) * (t-3)

equating 1 & 2

(n-15) * (t+4) = (n+20) * (t-3)

7n = 35t
n =5t

x= n * n/5

substituting this value in 1
n * n/5 = (n-15) * (n/5+4)

5n = 300
n =60

Hence E is the answer
1 KUDOS received
Intern
Intern
avatar
Joined: 02 Apr 2012
Posts: 3
Followers: 0

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

Re: If a farmer sells 15 of his chickens, his stock of feed will [#permalink] New post 01 May 2012, 18:09
1
This post received
KUDOS
You are right with the approach..

But there is a mistake in your equation.

case 1 (X-15) x (D+4)
case 2 (X+20)x (D[highlight]+[/highlight]3)

It should be

case 1 (X-15) x (D+4)
case 2 (X+20)x (D[highlight]-[/highlight]3) , since he runs out of feed three days earlier.

Now, equate the cases you have got, cause the amount of the feed is the same in both the cases.

(X-15) x (D+4) = (X+20)x (D-3)

you will arrive at

X = 5*D

Since the amount of the feed is equal in all cases, we have,

(X-15) * (D+4) = X*D

Substitute D = X/5 in the above equation, you will get the answer as,

X = 60.
Manager
Manager
avatar
Joined: 27 Dec 2011
Posts: 52
Followers: 0

Kudos [?]: 3 [0], given: 11

Re: If a farmer sells 15 of his chickens, his stock of feed will [#permalink] New post 13 Sep 2012, 23:26
Hi,

Instead of substituting values and all, we can do the following:

'x' be no. of chickens
't' be the time the feed last following normal schedule.

We two equations:
(x-15)(t+4)=1 [ Its like Rate*time=1 ('1' because the complete feed is done, i.e. complete work is done)] ------------- eq. 1
(x+20)(t-3)=1 [same explanation as above] ------------- eq. 2

From eq.1 find t = .... (it will have x)
From eq. 2 find t= ..... (it will also have x)

just equate 't' from above to equations and find x.

I must admit the calculations get hard as a quadratic equation is formed!

thanks,

-Kartik
Re: If a farmer sells 15 of his chickens, his stock of feed will   [#permalink] 13 Sep 2012, 23:26
    Similar topics Author Replies Last post
Similar
Topics:
1 If a farmer sells 15 of his chickens, his stock of feed will gmatgeek 1 12 Dec 2012, 12:43
2 Experts publish their posts in the topic A farmer spent $35 on feed for chickens and goats. He spent lamania 5 21 Apr 2012, 09:03
14 Experts publish their posts in the topic If the farmer sells 75 of his chickens, his stock of feed slingfox 11 25 Oct 2009, 01:41
A poor farmer was fond of telling his children: In this WinWinMBA 16 01 Jun 2005, 15:54
A poor farmer was fond of telling his children: In this saurya_s 10 18 Feb 2005, 15:38
Display posts from previous: Sort by

If a farmer sells 15 of his chickens, his stock of feed will

  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®.