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

 It is currently 23 Sep 2014, 10:27

### 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

# At a certain food stand, the price of each apple is ¢ 40 and

 Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:
Manager
Joined: 28 Feb 2010
Posts: 176
WE 1: 3 (Mining Operations)
Followers: 4

Kudos [?]: 20 [1] , given: 33

At a certain food stand, the price of each apple is ¢ 40 and [#permalink]  07 Jun 2010, 01:31
1
KUDOS
00:00

Difficulty:

85% (hard)

Question Stats:

49% (03:51) correct 51% (02:34) wrong based on 85 sessions
At a certain food stand, the price of each apple is ¢ 40 and the price of each orange is ¢ 60. Mary selects a total of 10 apples and oranges from the food stand, and the average (arithmetic mean) price of the 10 pieces of fruit is ¢ 56. How many oranges must Mary put back so that the average price of the pieces of fruit that she keeps is ¢ 52?

A. 1
B. 2
C. 3
D. 4
E. 5
[Reveal] Spoiler: OA

_________________

Regards,
Invincible...
"The way to succeed is to double your error rate."
"Most people who succeed in the face of seemingly impossible conditions are people who simply don't know how to quit."

Manager
Joined: 03 May 2010
Posts: 89
WE 1: 2 yrs - Oilfield Service
Followers: 11

Kudos [?]: 67 [0], given: 7

Re: Food Stand [#permalink]  07 Jun 2010, 03:18
A + O = 10 .....1

\frac{40A + 60O}{10} = 56

=> 2A + 3O = 28

Substitute equation 1:

=> 2A + 3*(10-A) = 28

=> 2A + 30 - 3A = 28

=> A = 2 From 1: O = 8

Let's say she put back "r" oranges.

=> \frac{40*2 + 60*(8 - r)}{10 - r} = 52

=> 80 + 480 - 60r = 520 - 52r

=> 8r = 40

r = 5

Pick E
Manager
Joined: 16 Jun 2010
Posts: 187
Followers: 2

Kudos [?]: 30 [0], given: 5

Re: Food Stand [#permalink]  02 Aug 2010, 14:51
This is a funny question.
I also solved and got the answer as 2, and after checking AbhayPrasanna's method the answer can also be 5 as demonstrated and if u substitue for 6 Oranges and 4 Apples or 3 Oranges and 7 Apples, the average turns out to be 52cents.

So is the question wrong or am I missing something here ?
_________________

Please give me kudos, if you like the above post.
Thanks.

Manager
Joined: 20 Mar 2010
Posts: 84
Followers: 2

Kudos [?]: 48 [0], given: 1

Re: Food Stand [#permalink]  02 Aug 2010, 18:56
devashish wrote:
This is a funny question.
I also solved and got the answer as 2, and after checking AbhayPrasanna's method the answer can also be 5 as demonstrated and if u substitue for 6 Oranges and 4 Apples or 3 Oranges and 7 Apples, the average turns out to be 52cents.

So is the question wrong or am I missing something here ?

As per the first two statements in the question(A+0=10 and (.4A+.6O)/10=5.6) no of apples is 2.
The last statement specified that she must put back only oranges to make the average 52cents. The no of apples should still remain 2 and can't change.
_________________

___________________________________
Please give me kudos if you like my post

Manager
Status: Waiting to hear from University of Texas at Austin
Joined: 24 May 2010
Posts: 76
Location: Changchun, China
Schools: University of Texas at Austin, Michigan State
Followers: 5

Kudos [?]: 40 [0], given: 4

Re: Food Stand [#permalink]  02 Aug 2010, 19:28
Here is my work (after I realized I could only put back oranges and not switch an orange for an apple)

a=apples
o=oranges
t=total

10 = a + o
5.60 = .4a-.6o
Substitute
5.60 = .4a-.6(10-a)
solution is a=2
10 = 2 + o
o=8

So we have 8 oranges and 2 apples

5.20(t-2)=.4(2)-.6(t-2)
solution is t=5

Total - Apples = Oranges
5 - 2 = 3

In the beginning there were 8 oranges, now there are 3 so we must have given back 5. E!
Manager
Joined: 06 Oct 2009
Posts: 98
Location: Mexico
Concentration: Entrepreneurship, Finance
GMAT 1: 610 Q42 V34
GPA: 3.85
WE: Sales (Commercial Banking)
Followers: 1

Kudos [?]: 34 [0], given: 3

Re: Food Stand [#permalink]  02 Aug 2010, 20:08
My answer is B = 2

With the help of the alligation Rule we can determine the original ratio as being 2:8

Alligation Rule (Cost of the Highest item less the Mean Cost) : (Mean Cost minus Lowest Cost Item)

(60 - 56) : (56 - 40 )

(4) : (16) = 2 : 8

So, utilizing the same rule for the new Mean 52

We get

(60 - 52) : (52 - 40)
8 : 12
4 : 6
Therefore the answer is 2... B
Regards from Mexico City!
Intern
Joined: 14 Dec 2012
Posts: 2
Followers: 0

Kudos [?]: 0 [0], given: 4

Re: Food Stand [#permalink]  09 Dec 2013, 21:32
Answer should be E.

Solving by Alligations:

40------------60

56

(60-56) (56-40)
4-------------16

Apples:Oranges = 1:4

There are 10 fruits so that means Apples =2 Oranges = 8

Now the Average Price is 52 so again using alligation:

40----------60

52

(60-52) (52-40)
8 12

They are in 8:12 or 2:3 ratio. Now no of apples are still 2 since we only need to reduce oranges as per question. So assume there are x no of fruits.

so, 2/5*x = 2

x = 5.

So we have 5 fruits. 2 Apples and 3 Oranges. Intitally we had 8 oranges and now 3 oranges that means 5 oranges needs to be kept back in the basket.

Hence ans should be E.
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 4791
Location: Pune, India
Followers: 1123

Kudos [?]: 5106 [0], given: 164

Re: Food Stand [#permalink]  09 Dec 2013, 22:10
Expert's post
praveenism wrote:
Q3:
At a certain food stand, the price of each apple is ¢ 40 and the price of each orange is ¢ 60. Mary
selects a total of 10 apples and oranges from the food stand, and the average (arithmetic mean)
price of the 10 pieces of fruit is ¢ 56. How many oranges must Mary put back so that the average
price of the pieces of fruit that she keeps is ¢ 52?
A. 1
B. 2
C. 3
D. 4
E. 5

[Reveal] Spoiler:
Answer:E. I solved the question and got ans as 2

The correct answer is (E). People who are getting (B) need to think about this: The second time when the average is 52, does Mary still have 10 fruits? She ONLY needs to put back oranges. Not replace them with apples. So when you use alligation again and get the ratio as 2:3, you don't get 6 oranges since total number of fruits are not known. Let me solve it step by step.

When avg = 56

wa/wo = (60 - 56)/(56 - 40) = 1/4
So number of apples = 2, number of oranges = 8

When avg - 52
wa/wo = (60 - 52)/(52 - 40) = 2/3
What is the total number of fruit now? We don't know. We know Mary put back some oranges. We don't know how many. What we do know is that then number of apples she had stayed the same. She had 2 apples before so she still has 2 apples. If number of apples now is 2, number of oranges must be 3. So she must have put back 8 - 3 = 5 oranges.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options. Veritas Prep Reviews Intern Joined: 11 Jul 2013 Posts: 27 Followers: 0 Kudos [?]: 0 [0], given: 23 Re: At a certain food stand, the price of each apple is ¢ 40 and [#permalink] 21 Sep 2014, 01:36 VeritasPrepKarishma wrote: praveenism wrote: Q3: At a certain food stand, the price of each apple is ¢ 40 and the price of each orange is ¢ 60. Mary selects a total of 10 apples and oranges from the food stand, and the average (arithmetic mean) price of the 10 pieces of fruit is ¢ 56. How many oranges must Mary put back so that the average price of the pieces of fruit that she keeps is ¢ 52? A. 1 B. 2 C. 3 D. 4 E. 5 [Reveal] Spoiler: Answer:E. I solved the question and got ans as 2 The correct answer is (E). People who are getting (B) need to think about this: The second time when the average is 52, does Mary still have 10 fruits? She ONLY needs to put back oranges. Not replace them with apples. So when you use alligation again and get the ratio as 2:3, you don't get 6 oranges since total number of fruits are not known. Let me solve it step by step. When avg = 56 wa/wo = (60 - 56)/(56 - 40) = 1/4 So number of apples = 2, number of oranges = 8 When avg - 52 wa/wo = (60 - 52)/(52 - 40) = 2/3 What is the total number of fruit now? We don't know. We know Mary put back some oranges. We don't know how many. What we do know is that then number of apples she had stayed the same. She had 2 apples before so she still has 2 apples. If number of apples now is 2, number of oranges must be 3. So she must have put back 8 - 3 = 5 oranges. can we do it like this let no of apples be a and no of oranges be b total fruits initially 10 so 56(10) = 40 ( a)+ 60( 10 -a) second case when avg is 52 ...let no of organes she kept away be r so 52( 10-r) = 40 ( a) + 60( 10-a-r) -------------2 we need not solves anything up till this point now we know that the reduction in total is cause only by no of oranges she kept away , let us say she kept away r orhanges so reduction is ( 56(10) - 52( 10-r) = 4(10) + 52 r ----3 we know that reduction will be equal to 60 r as in equation 2 .....is same as equation 1 expcept for the amount accouhnted for reduced oranges so using 3 4(10)=52r = 60 r r=5 Re: At a certain food stand, the price of each apple is ¢ 40 and [#permalink] 21 Sep 2014, 01:36 Similar topics Replies Last post Similar Topics: At a certain food stand, the price of each apple is 40 and 1 05 Nov 2008, 15:27 At a certain food stand, the price of each apple is$0.4 and 9 14 Oct 2007, 02:53
At a fruit stand yesterday, the price of each apple was 2 01 Jul 2007, 06:52
At a fruit stand yesterday, the price of each apple was 1 31 Jan 2007, 05:15
Q 8. At a certain food stand, the price of each apple is 9 10 Oct 2005, 11:45
Display posts from previous: Sort by

# At a certain food stand, the price of each apple is ¢ 40 and

 Question banks Downloads My Bookmarks Reviews Important topics

 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®.