Last visit was: 25 Apr 2024, 11:31 It is currently 25 Apr 2024, 11:31
Decision Tracker
My Rewards
New comers' posts
New posts
Unanswered

Close

GRE Prep 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 GRE 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.

Go to My Error Log Learn more
Close

Request Expert Reply

Confirm Cancel
PREVIOUS TOPIC
NEXT TOPIC

Machine X and machine Y are the only two machines used

Tags :
Find Similar Topics  About  Add a Tag

Show Tags
Hide Tags

avatar
gulsam
Intern
Intern
Joined: 12 Nov 2018
Posts: 47
Own Kudos [?]: 35 [13]
Given Kudos: 0
Send PM
Machine X and machine Y are the only two machines used [#permalink] New post   Updated on: 28 Dec 2019, 07:20
1
12
Bookmarks
00:00

Question Stats:

62% (01:12) correct 37% (01:16) wrong based on 264 sessions

Hide Show timer Statistics

Machine X and machine Y are the only two machines used to fill bottles of Zap Cola for a certain shipment. X fills each bottle in the shipment with 584 milliliters of cola. Y fills each bottle in a shipment with 594 milliliters of cola. Bottles of Zap Cola in the shipment contain an average of 590 milliliters of cola.


Quantity A
Quantity B
The number of bottles in the shipment filled by machine Y
The number of bottles in the shipment filled by machine X






A.Quantity A is greater
B.Quantity B is greater
C.The two quantities are equal.
D.The relationship cannot be determined from the information given.
ShowHide Answer
Official Answer
A

Originally posted by gulsam on 28 Dec 2019, 07:07.
Last edited by gulsam on 28 Dec 2019, 07:20, edited 5 times in total.
avatar
gulsam
Intern
Intern
Joined: 12 Nov 2018
Posts: 47
Own Kudos [?]: 35 [3]
Given Kudos: 0
Send PM
Re: Machine X and machine Y are the only two machines used [#permalink] New post   28 Dec 2019, 07:10
3
This is a weighted average problem. While it is not possible to know precisely how many bottles each machine fills, it is possible to determine the ratio between them. Consider first what would happen if X fills only one bottle and Y fills only one bottle as well. So the average for the shipment would simply be an average of 584 to 594. On the other hand, if X filled all of the bottles, then the average of the shipment would be 584; if Y filled all of the bottles, the average would be 594.

This simple thought experiment shows that as a machine makes more of a contribution to the shipment, the overall average is pulled closer to that machine. Since the average is closer to the average of Y than it is to the average of X, machine Y must have contributed more to the shipment than X, and thus must have filled more bottles.

In addition, we can get even more definite with this. Since there is a difference of 10 between the average of X and Y, and since the overall average is 6 greater than the average of X (or 4 less than the average of Y), Y must fill 6/10ths of the bottles, and X must fill 4/10ths.

The correct answer is B.
avatar
gulsam
Intern
Intern
Joined: 12 Nov 2018
Posts: 47
Own Kudos [?]: 35 [0]
Given Kudos: 0
Send PM
Re: Machine X and machine Y are the only two machines used [#permalink] New post   29 Dec 2019, 05:16
Carcass wrote:
Please sir follow the rules to format properly a QCQ.

They are at the top of the quant section.

Regards


Thanks, I see
avatar
faycalshb
Intern
Intern
Joined: 02 Jan 2020
Posts: 5
Own Kudos [?]: 0 [0]
Given Kudos: 0
Concentration: Real Estate, Finance
Schools: AGSM '22
WE:Asset Management (Real Estate)
Send PM
Re: Machine X and machine Y are the only two machines used [#permalink] New post   02 Jan 2020, 07:38
can someone provide the correct answer to this question ?
avatar
S
FCOCGALVAN
Manager
Manager
Joined: 01 Dec 2018
Posts: 87
Own Kudos [?]: 35 [2]
Given Kudos: 38
Send PM
Re: Machine X and machine Y are the only two machines used [#permalink] New post   28 Feb 2020, 17:10
2
Hello @Carcass

Can we solve using weighted averages?

x/y = (594-590)/(590-584)...

x/y = 2/3

Hence y is bigger that x in proportion and then the answer will be A.

Ans A
User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 28635
Own Kudos [?]: 33117 [0]
Given Kudos: 25175
Send PM
Re: Machine X and machine Y are the only two machines used [#permalink] New post   29 Feb 2020, 00:07
2
Expert Reply
FCOCGALVAN wrote:
Hello @Carcass

Can we solve using weighted averages?

x/y = (594-590)/(590-584)...

x/y = 2/3

Hence y is bigger that x in proportion and then the answer will be A.

Ans A


of course :)

here a video by Ron

Efficient Choice of Variables in Word Problems, and Weighted Averages

avatar
S
FCOCGALVAN
Manager
Manager
Joined: 01 Dec 2018
Posts: 87
Own Kudos [?]: 35 [0]
Given Kudos: 38
Send PM
Re: Machine X and machine Y are the only two machines used [#permalink] New post   02 Mar 2020, 16:19
@Carcass

How would it be solved usidn weighted averages?

Im doin smthing wrogn cuz im getting A as answer.

Kind regards!
User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 28635
Own Kudos [?]: 33117 [1]
Given Kudos: 25175
Send PM
Re: Machine X and machine Y are the only two machines used [#permalink] New post   03 Mar 2020, 05:54
1
Expert Reply
584 ---------- X ------------- 590 ------ Y ------ 594

X is 6 and Y is 4

In the average X has a more specific weight

B is the answer
avatar
Asif123
Manager
Manager
Joined: 28 Mar 2019
Status:Job holder
Posts: 108
Own Kudos [?]: 91 [0]
Given Kudos: 0
Location: Bangladesh
Mohammad Alamin Asif: Mohammad Alamin Asif
Send PM
Re: Machine X and machine Y are the only two machines used [#permalink] New post   03 Mar 2020, 10:43
2
584x + 594x = 590
or, x = 0.5
so that X machine = 584x = 584*.5= 292
Y Machine = 594*.5= 297
B is the answer
avatar
DeadDemon
Intern
Intern
Joined: 15 Mar 2020
Posts: 24
Own Kudos [?]: 31 [0]
Given Kudos: 0
Send PM
Re: Machine X and machine Y are the only two machines used [#permalink] New post   22 Apr 2020, 08:37
2
Carcass wrote:
584 ---------- X ------------- 590 ------ Y ------ 594

X is 6 and Y is 4

In the average X has a more specific weight

B is the answer


B - wrong answer!

if y = 4 means that the weight of Y should be higher.
Suppose - we have 10X and 10Y - the mean is (10*584 + 10*594)/20 = 589
The mean = 590 requires that Y should be higher than X. In our case, if X=10, Y=15 that makes mean 590. If Y < X - the mean will always be less than 589.

Answer A is correct.
User avatar
P
GreenlightTestPrep
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 11681 [2]
Given Kudos: 136
Send PM

Top Member of the Month
Re: Machine X and machine Y are the only two machines used [#permalink] New post   22 Apr 2020, 09:00
2
gulsam wrote:
Machine X and machine Y are the only two machines used to fill bottles of Zap Cola for a certain shipment. X fills each bottle in the shipment with 584 milliliters of cola. Y fills each bottle in a shipment with 594 milliliters of cola. Bottles of Zap Cola in the shipment contain an average of 590 milliliters of cola.


Quantity A
Quantity B
The number of bottles in the shipment filled by machine Y
The number of bottles in the shipment filled by machine X



ASIDE--------------------
Key concept: If we combine EQUAL amounts of two populations, then the average of those two populations COMBINED will equal the AVERAGE of those two populations
For example, let's say solution A is 30% salt, and solution B is 40% salt.
If we combine EQUAL amounts of solution A and solution B, the concentration of the resulting mixture = (30 + 40)/2 = 35
So the resulting mixture is 35% salt.
------------------------

GIVEN:
Machine X bottles contain (on average) 584 ml
Machine Y bottles contain (on average) 594 ml

If we were to combine an EQUAL number of bottles from each machine, then the average volume of the COMBINED population = (584 + 594)/2 = 589 ml

GIVEN: The COMBINED shipment has an average volume of 590 ml
Since 590 is closer to Machine Y's average volume (of 594 ml) than it is to Machine X's average volume (of 584 ml), we know that the COMBINED shipment must contain more bottles from Machine Y.

Answer: A

The above concepts are described in greater detail in the following video:
User avatar
P
GreenlightTestPrep
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 11681 [1]
Given Kudos: 136
Send PM

Top Member of the Month
Re: Machine X and machine Y are the only two machines used [#permalink] New post   22 Apr 2020, 09:03
1
FCOCGALVAN wrote:
@Carcass

How would it be solved usidn weighted averages?

Im doin smthing wrogn cuz im getting A as answer.

Kind regards!


You're right. The correct answer is A. It looks like the original poster added the wrong answer.
I've now corrected the original post.
avatar
B
Adewale
Intern
Intern
Joined: 04 Dec 2021
Posts: 28
Own Kudos [?]: 26 [0]
Given Kudos: 24
Send PM
Re: Machine X and machine Y are the only two machines used [#permalink] New post   09 Jul 2022, 03:06
Can someone say what is wrong with this calculation.

Total volume in shipment if n is number of bottles= 590n.
Number of bottles filled by X = 590n/584= 1.010273573n
Number of bottles filled by Y = 590n/594= 0.993265993n
Since n must be a positive integer B is greater.
User avatar
P
GreenlightTestPrep
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 11681 [1]
Given Kudos: 136
Send PM

Top Member of the Month
Re: Machine X and machine Y are the only two machines used [#permalink] New post   09 Jul 2022, 06:41
1
Adewale wrote:
Can someone say what is wrong with this calculation.

Total volume in shipment if n is number of bottles= 590n.
Number of bottles filled by X = 590n/584= 1.010273573n
Number of bottles filled by Y = 590n/594= 0.993265993n
Since n must be a positive integer B is greater.


Presumably, n is the TOTAL number of bottles in the shipment (including bottles filled by machine X and bottles filled by machine Y).
So, 590n = the TOTAL volume of cola in the entire shipment.

Now you need to ask yourself, "What does it mean when I write: X = 590n/584= 1.010273573n?"
Hint: Notice that 1.010273573n is greater than n.
So, what does 1.010273573n mean?
avatar
B
Adewale
Intern
Intern
Joined: 04 Dec 2021
Posts: 28
Own Kudos [?]: 26 [0]
Given Kudos: 24
Send PM
Re: Machine X and machine Y are the only two machines used [#permalink] New post   09 Jul 2022, 09:33
Okay Brent. I understand the question but why did the calculation lead me there?
avatar
B
KC15
Intern
Intern
Joined: 08 Aug 2022
Posts: 49
Own Kudos [?]: 33 [1]
Given Kudos: 98
Send PM
Re: Machine X and machine Y are the only two machines used [#permalink] New post   14 Aug 2022, 15:55
1
First of all, we can just see that 590 is close to the amount 594 than it is of 584, so without any calculations, the answer is clearly machine Y (A). However, I didn't see this at first, so here is the calculation I did:

X = fraction of bottles filled by machine X
Y = fraction of bottles filled by machine Y = 1-X

584X + 594Y = 590 --> 584X + 594(1-X) = 590
584X - 594X + 594 = 590
-10X = -4
X = 4/10 (meaning 4/10 bottles are filled by machine X), which means Y = 6/10
So more bottles are filled by machine Y --> answer A
Prep Club for GRE Bot
gmatclubot
[#permalink]
Moderators:
BrushMyQuant
Moderator
1085 posts
VibhuAnurag
GRE Instructor
218 posts

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

Main navigation

Partners

GRE Resources

www.ets.org/gre | About | Terms and Conditions and Privacy Policy | Prep Club for GRE Rules | Contact