Last visit was: 26 Apr 2024, 05:05 It is currently 26 Apr 2024, 05:05

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
SORT BY:
Date
User avatar
Intern
Intern
Joined: 13 Jun 2005
Posts: 11
Own Kudos [?]: 155 [141]
Given Kudos: 0
Send PM
Most Helpful Reply
User avatar
Manager
Manager
Joined: 21 Jun 2006
Posts: 155
Own Kudos [?]: 534 [56]
Given Kudos: 0
Send PM
Math Expert
Joined: 02 Sep 2009
Posts: 92929
Own Kudos [?]: 619151 [49]
Given Kudos: 81609
Send PM
General Discussion
User avatar
Senior Manager
Senior Manager
Joined: 26 Feb 2006
Posts: 384
Own Kudos [?]: 583 [6]
Given Kudos: 0
Send PM
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
2
Kudos
3
Bookmarks
dred wrote:
A convenience store currently stocks 48 bottles of mineral water. The bottles have two sizes of either 20 or 40 ounces each. The average volume per bottle the store currently has in stock is 35 ounces. How many 40 ounce bottles must be sold for the average volume per bottle to be reduced to 25 ounces if no 20 ounce bottles are sold?
10
20
30
32
34


D.

20 p + 40 (1-p) = 35
p = 1/4
so 20 oz = 12

12 x 20 / (12+x) + 40x / (12+x) = 25

x = 4
so 32 bottles with 40 oz should be sold.
User avatar
Director
Director
Joined: 04 May 2006
Posts: 866
Own Kudos [?]: 6811 [13]
Given Kudos: 1
Concentration: Finance
Schools:CBS, Kellogg
Send PM
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
8
Kudos
5
Bookmarks
GGUY wrote:
Taken From MGMAT # 3

A convenience store currently stocks 48 bottles of mineral water. The bottles have two sizes of either 20 or 40 ounces each. The average volume per bottle the store currently has in stock is 35 ounces. How many 40 ounce bottles must be sold for the average volume per bottle to be reduced to 25 ounces if no 20 ounce bottles are sold?

(A) 10
(B) 20
(C) 30
(D) 32
(E) 34

Please Explain

D

20x + 40y = 35*48

20x + 40 (y-t) = 25*(48-t)
20x + 40y -40t = 25*48 - 25t
35*48 -40t = 25*48 -25t
t =32
avatar
Intern
Intern
Joined: 08 Dec 2013
Posts: 25
Own Kudos [?]: 6 [1]
Given Kudos: 23
Send PM
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
1
Kudos
hey can any1 plz tell me ..
if ques says that no 20 ounce bottles are sold..
then y r we considering "20*12" while calculating the new ratio..
wats the meaning and the use of that line above.." no 20 ounce bottles are sold"
y can`t we directly put 0 bottles for 20 ounces..

y can`t we go directly for ..

25=(20(0)+40(x))/x..

confused..:(
avatar
Intern
Intern
Joined: 08 Dec 2013
Posts: 25
Own Kudos [?]: 6 [1]
Given Kudos: 23
Send PM
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
1
Kudos
hi thanx for ur valuable answer but i`ll be glad if u could put it algebrically...that will be more easier for me to understand.

also, plz tell me wat is the point of "20 ounces bottles not sold" ... y r we still considering that while calculating the new ratio..it should be 0 ..huh..
Math Expert
Joined: 02 Sep 2009
Posts: 92929
Own Kudos [?]: 619151 [2]
Given Kudos: 81609
Send PM
A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
2
Kudos
Expert Reply
shreygupta3192 wrote:
hi thanx for ur valuable answer but i`ll be glad if u could put it algebrically...that will be more easier for me to understand.

also, plz tell me wat is the point of "20 ounces bottles not sold" ... y r we still considering that while calculating the new ratio..it should be 0 ..huh..


Algebraic ways are given in posts above.

As for your other question. I think you misunderstood the problem.

There are 12 20-ounce and 36 40-ounce bottles. The average volume of those 48 bottles is 35 ounces.

We need to find how many of 36 40-ounce bottles must be sold for the average volume of the remaining bottles to be reduced to 25 ounces.
Manager
Manager
Joined: 24 Jun 2014
Posts: 53
Own Kudos [?]: 48 [4]
Given Kudos: 105
Concentration: Social Entrepreneurship, Nonprofit
Send PM
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
4
Kudos
shreygupta3192 wrote:
hi thanx for ur valuable answer but i`ll be glad if u could put it algebrically...that will be more easier for me to understand.

also, plz tell me wat is the point of "20 ounces bottles not sold" ... y r we still considering that while calculating the new ratio..it should be 0 ..huh..


Shrey,


We can establish from question

here x is number of 20 ounce bottles , y is 40 ounce bottles
x+y=48
20x+40y=1680

x=12,y=36
Coming to remaining part of question

Value of 20 ounce bottles will be 0 , if we consider the bottles sold.

20x+40z=25(x+z);

z = remaining bottles
x=12 , no removal here
20*12+40(z)=25(12+z);z=4

if remaining is 4 ,then 36-4 were sold=32.

However Brunel's approach is good time saving approach.
avatar
Intern
Intern
Joined: 12 Oct 2014
Posts: 42
Own Kudos [?]: 21 [0]
Given Kudos: 241
Location: India
Concentration: Finance, General Management
GMAT 1: 550 Q44 V21
WE:Analyst (Investment Banking)
Send PM
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
Bunuel wrote:
shreygupta3192 wrote:
A convenience store currently stocks 48 bottles of mineral water. The bottles have two sizes of either 20 or 40 ounces each. The average volume per bottle the store currently has in stock is 35 ounces. How many 40 ounce bottles must be sold for the average volume per bottle to be reduced to 25 ounces if no 20 ounce bottles are sold?

(A) 10
(B) 20
(C) 30
(D) 32
(E) 34

hey can any1 plz tell me ..
if ques says that no 20 ounce bottles are sold..
then y r we considering "20*12" while calculating the new ratio..
wats the meaning and the use of that line above.." no 20 ounce bottles are sold"
y can`t we directly put 0 bottles for 20 ounces..

y can`t we go directly for ..

25=(20(0)+40(x))/x..

confused..:(


No. The question asks about the average weight of bottles which are not sold.

A convenience store currently stocks 48 bottles of mineral water. The bottles have two sizes of either 20 or 40 ounces each. The average volume per bottle the store currently has in stock is 35 ounces. How many 40 ounce bottles must be sold for the average volume per bottle to be reduced to 25 ounces if no 20 ounce bottles are sold?

(A) 10
(B) 20
(C) 30
(D) 32
(E) 34

The current average of 20 (35 - 15) and 40-ounce (40 - 5) bottles is 35, thus there must be 3 times as many 40-ounce bottles as 20-ounce bottles. Since there are total of 48 bottles, then there must be 12 20-ounce bottles and 36 40-ounce bottles.

Now, we need to sell ONLY 40-ounce bottles so that the average to become 25. Same way, 25 is 5 away from 20 and 15 away from 40, so after selling some number of 40-ounce bottles, there must be 3 times as many 20-ounce bottles as 40-ounce bottles. So, there must be 12 20-ounce bottles and 12/3 = 4 40-ounce bottles.

Therefore, 36 - 4 = 32 40-ounce bottles must be sold.

Answer: D.

Hope it's clear.



Fantastic solution Bunuel, you are a legend !! :)
User avatar
Manager
Manager
Joined: 26 Apr 2013
Status:folding sleeves up
Posts: 101
Own Kudos [?]: 702 [4]
Given Kudos: 39
Location: India
Concentration: Finance, Strategy
GMAT 1: 530 Q39 V23
GMAT 2: 560 Q42 V26
GPA: 3.5
WE:Consulting (Computer Hardware)
Send PM
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
2
Kudos
2
Bookmarks
dred wrote:
A convenience store currently stocks 48 bottles of mineral water. The bottles have two sizes of either 20 or 40 ounces each. The average volume per bottle the store currently has in stock is 35 ounces. How many 40 ounce bottles must be sold for the average volume per bottle to be reduced to 25 ounces if no 20 ounce bottles are sold?
10
20
30
32
34


You can also resolve this question with weighted avg formula

20 40
\ /
35
/ \
15 5

Ratio : 3: 1 or we can say that 40 ounce bottles are three time as many as 20 ounce

so number of 40 ounce bottles are 36 and 20 ounce bottles are 12

next (20(12)+ 40x)/12+x = 25 -->where x is the remaining 40 ounce bottles

x= 4 i.e. 36-4=> 32 of 40 ounce bottles have been sold
Alum
Joined: 12 Aug 2015
Posts: 2282
Own Kudos [?]: 3131 [0]
Given Kudos: 893
GRE 1: Q169 V154
Send PM
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
its taking a bit longer to solve using the algebraic approach..
Anyone with any other approach?
Regards
CC- Abhishek009
StoneCold
RC & DI Moderator
Joined: 02 Aug 2009
Status:Math and DI Expert
Posts: 11179
Own Kudos [?]: 31943 [5]
Given Kudos: 290
Send PM
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
3
Kudos
2
Bookmarks
Expert Reply
stonecold wrote:
its taking a bit longer to solve using the algebraic approach..
Anyone with any other approach?
Regards
CC- Abhishek009
StoneCold


Hi,
the other method would be weighted average method.. people have already used it above, still ill do it once again..

TWO steps..


first - initial numbers
20 and 40 avail and average is 35..
so \(\frac{# of 20}{# of 40} = \frac{40-35}{35-20} = \frac{1}{3}\)
so # of 20 \(= \frac{1}{1+3} *48 =12\)..
and # of 40 ounces = 48-12 = 36

second -
20 and 40 avail and average is 25..
so\(\frac{# of 20}{# of 40} = \frac{40-25}{25-20} =\frac{3}{1}\)
so # of 20\(= \frac{3}{1+3} *x =12\), here we know # of 20 ounces remains constant..
so x= 16
and # of 40 ounces = 16-12 = 4..
now # of 40 ounces bottle sold = 36-4 = 32
IIM School Moderator
Joined: 04 Sep 2016
Posts: 1261
Own Kudos [?]: 1240 [0]
Given Kudos: 1207
Location: India
WE:Engineering (Other)
Send PM
A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
chetan2u Bunuel VeritasPrepKarishma niks18

Quote:
A convenience store currently stocks 48 bottles of mineral water.
The bottles have two sizes of either 20 or 40 ounces each. The average
volume per bottle the store currently has in stock is 35 ounces. How many 40
ounce bottles must be sold for the average volume per bottle to be reduced to 25
ounces if no 20 ounce bottles are sold?

Quote:
Hi,
the other method would be weighted average method.. people have already used it above, still ill do it once again..

TWO steps..


first - initial numbers
20 and 40 avail and average is 35..
so \(\frac{# of 20}{# of 40} = \frac{40-35}{35-20} = \frac{1}{3}\)
so # of 20 \(= \frac{1}{1+3} *48 =12\)..
and # of 40 ounces = 48-12 = 36

second -
20 and 40 avail and average is 25..
so\(\frac{# of 20}{# of 40} = \frac{40-25}{25-20} =\frac{3}{1}\)
so # of 20\(= \frac{3}{1+3} *x =12\), here we know # of 20 ounces remains constant..
so x= 16
and # of 40 ounces = 16-12 = 4..
now # of 40 ounces bottle sold = 36-4 = 32


question stem says:if no 20 ounce bottles are sold, meaning no bottles are sold at all , not : additional bottles are not sold.
Are we on same page?
Retired Moderator
Joined: 25 Feb 2013
Posts: 895
Own Kudos [?]: 1527 [0]
Given Kudos: 54
Location: India
GPA: 3.82
Send PM
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
adkikani wrote:
chetan2u Bunuel VeritasPrepKarishma niks18

Quote:
A convenience store currently stocks 48 bottles of mineral water.
The bottles have two sizes of either 20 or 40 ounces each. The average
volume per bottle the store currently has in stock is 35 ounces. How many 40
ounce bottles must be sold for the average volume per bottle to be reduced to 25
ounces if no 20 ounce bottles are sold?

Quote:
Hi,
the other method would be weighted average method.. people have already used it above, still ill do it once again..

TWO steps..


first - initial numbers
20 and 40 avail and average is 35..
so \(\frac{# of 20}{# of 40} = \frac{40-35}{35-20} = \frac{1}{3}\)
so # of 20 \(= \frac{1}{1+3} *48 =12\)..
and # of 40 ounces = 48-12 = 36

second -
20 and 40 avail and average is 25..
so\(\frac{# of 20}{# of 40} = \frac{40-25}{25-20} =\frac{3}{1}\)
so # of 20\(= \frac{3}{1+3} *x =12\), here we know # of 20 ounces remains constant..
so x= 16
and # of 40 ounces = 16-12 = 4..
now # of 40 ounces bottle sold = 36-4 = 32


question stem says:if no 20 ounce bottles are sold, meaning no bottles are sold at all , not : additional bottles are not sold.
Are we on same page?


Hi adkikani

Yes you are right in your assessment that no new 20 ounce bottles are added or sold.

In the second part of the solution, "x" denotes the total number of bottles left after selling 40 ounce bottles. In this solution number of 20 ounce bottle remains 12. So on solving, we get x=16 i.e. only 16 bottles are left after 40 ounce bottles are sold. so out of 16, 12 are 20 ounce bottles and the remaining 4 are 40 ounce bottles. As there are 36, 40 ounce bottles, so 36-4=32, 40 ounce bottles were sold.
Intern
Intern
Joined: 26 Sep 2020
Status:I'm done with GMAT.
Posts: 34
Own Kudos [?]: 19 [0]
Given Kudos: 195
Location: India
Concentration: Marketing, Entrepreneurship
GMAT 1: 630 Q44 V32
GMAT 2: 690 Q48 V38
GMAT 3: 700 Q48 V37
GPA: 1
WE:General Management (Retail)
Send PM
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
Bunuel wrote:
shreygupta3192 wrote:
A convenience store currently stocks 48 bottles of mineral water. The bottles have two sizes of either 20 or 40 ounces each. The average volume per bottle the store currently has in stock is 35 ounces. How many 40 ounce bottles must be sold for the average volume per bottle to be reduced to 25 ounces if no 20 ounce bottles are sold?

(A) 10
(B) 20
(C) 30
(D) 32
(E) 34

hey can any1 plz tell me ..
if ques says that no 20 ounce bottles are sold..
then y r we considering "20*12" while calculating the new ratio..
wats the meaning and the use of that line above.." no 20 ounce bottles are sold"
y can`t we directly put 0 bottles for 20 ounces..

y can`t we go directly for ..

25=(20(0)+40(x))/x..

confused..:(


No. The question asks about the average weight of bottles which are not sold.

A convenience store currently stocks 48 bottles of mineral water. The bottles have two sizes of either 20 or 40 ounces each. The average volume per bottle the store currently has in stock is 35 ounces. How many 40 ounce bottles must be sold for the average volume per bottle to be reduced to 25 ounces if no 20 ounce bottles are sold?

(A) 10
(B) 20
(C) 30
(D) 32
(E) 34

The current average of 20 (35 - 15) and 40-ounce (40 - 5) bottles is 35, thus there must be 3 times as many 40-ounce bottles as 20-ounce bottles. Since there are total of 48 bottles, then there must be 12 20-ounce bottles and 36 40-ounce bottles.

Now, we need to sell ONLY 40-ounce bottles so that the average to become 25. Same way, 25 is 5 away from 20 and 15 away from 40, so after selling some number of 40-ounce bottles, there must be 3 times as many 20-ounce bottles as 40-ounce bottles. So, there must be 12 20-ounce bottles and 12/3 = 4 40-ounce bottles.

Therefore, 36 - 4 = 32 40-ounce bottles must be sold.

Answer: D.

Hope it's clear.


I think this is the only way to solve this question in under 2 minutes. Kudos Bunuel..
Tutor
Joined: 16 Oct 2010
Posts: 14828
Own Kudos [?]: 64931 [1]
Given Kudos: 427
Location: Pune, India
Send PM
A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
1
Kudos
Expert Reply
dred wrote:
A convenience store currently stocks 48 bottles of mineral water. The bottles have two sizes of either 20 or 40 ounces each. The average volume per bottle the store currently has in stock is 35 ounces. How many 40 ounce bottles must be sold for the average volume per bottle to be reduced to 25 ounces if no 20 ounce bottles are sold?

(A) 10
(B) 20
(C) 30
(D) 32
(E) 34


Use weighted averages formula discussed in this blog post: https://anaprep.com/arithmetic-weighted-averages/
and in this video: https://www.youtube.com/watch?v=_GOAU7moZ2Q

w1/w2 = (A2 - Aavg)/(Aavg - A1) = (40 - 35)/(35 - 20) = 1/3
Ratio of 20 ounce bottles : 40 ounce bottles = 1 : 3
So of the 48 bottles, 12 are 20-ounce bottles and 36 are 40-ounce bottles.

New Avg = 25
w1/w2 = (A2 - Aavg)/(Aavg - A1) = (40 - 25)/(25 - 20) = 3/1
New Ratio of 20 ounce bottles : 40 ounce bottles = 3 : 1
We still have 12 20-ounce bottles so we must have only 4 40-ounce bottles.

Hence from 36, the number of bottles of 40-ounces has dropped to 4. This means 32 bottles were sold.

Originally posted by KarishmaB on 18 Mar 2021, 04:09.
Last edited by KarishmaB on 18 Nov 2023, 02:07, edited 1 time in total.
Manager
Manager
Joined: 13 Jun 2019
Posts: 203
Own Kudos [?]: 92 [0]
Given Kudos: 646
GMAT 1: 490 Q42 V17
GMAT 2: 550 Q39 V27
GMAT 3: 630 Q49 V27
Send PM
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
The last sentence is so confusing.

How many 40 ounce bottles must be sold for the average volume per bottle to be reduced to 25 ounces if no 20 ounce bottles are sold?

i was thinking #20 is 0 and i made complete mess of this problem. :(

Not able to understand whether my concept is clear or not about weighted average.

Request to provide your inputs

Bunuel chetan2u VeritasKarishma
Tutor
Joined: 16 Oct 2010
Posts: 14828
Own Kudos [?]: 64931 [1]
Given Kudos: 427
Location: Pune, India
Send PM
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
1
Kudos
Expert Reply
rsrighosh wrote:
The last sentence is so confusing.

How many 40 ounce bottles must be sold for the average volume per bottle to be reduced to 25 ounces if no 20 ounce bottles are sold?

i was thinking #20 is 0 and i made complete mess of this problem. :(

Not able to understand whether my concept is clear or not about weighted average.

Request to provide your inputs

Bunuel chetan2u VeritasKarishma


You are given "no 20 ounce bottles are sold".
It means none of them are sold. So all 20 ounce bottles are still there.
If all 20 ounce bottles were sold, how could the average be anything other than 40 since there would be only 40 ounce bottles.
Intern
Intern
Joined: 11 Jan 2021
Posts: 15
Own Kudos [?]: 1 [0]
Given Kudos: 19
Send PM
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
Let, the 20-ounce bottles are x. So, 40-ounce Bottles will be 48-x
So, 20x+40(48-x)=48*35
So, x=12, & 40-ounce bottles will be 36.

Now, Let "a" 40-ounce bottle to be sold.
So, 20*12+40(36-a)= (48-a)*25
So, a=32 [Option D]
GMAT Club Bot
Re: A convenience store currently stocks 48 bottles of mineral water. The [#permalink]
 1   2   
Moderators:
Math Expert
92929 posts
Senior Moderator - Masters Forum
3137 posts

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