It is currently 18 Nov 2017, 11:05

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Material A costs $3 per kilogram, and Material B costs $5 per kilogram

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

3 KUDOS received
Intern
Intern
avatar
Joined: 09 Feb 2011
Posts: 12

Kudos [?]: 123 [3], given: 1

Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 11 Feb 2011, 02:26
3
This post received
KUDOS
62
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  85% (hard)

Question Stats:

54% (01:31) correct 46% (01:57) wrong based on 1904 sessions

HideShow timer Statistics

Material A costs $3 per kilogram, and Material B costs $5 per kilogram. If 10 kilograms of Material K consists of x kilograms of Material A and y kilograms of Material B, is x > y ?

(1) y > 4
(2) The cost of the 10 kilograms of Material K is less than $40.
[Reveal] Spoiler: OA

Last edited by Bunuel on 05 Aug 2017, 00:16, edited 3 times in total.
Edited the question and added the OA.

Kudos [?]: 123 [3], given: 1

Expert Post
11 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42249

Kudos [?]: 132595 [11], given: 12326

Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 11 Feb 2011, 03:50
11
This post received
KUDOS
Expert's post
22
This post was
BOOKMARKED
alltimeacheiver wrote:
Material A costs $3 per kilogram, and material B costs $5 per kilogram. If 10 kilograms of material K consists of x kilograms of material A and y kilograms of material B, is x >y?

(1) y > 4
(2) The cost of the 10 kilograms of material K is less than $40


Material A costs $3 per kilogram, and material B costs $5 per kilogram. If 10 kilograms of material K consists of x kilograms of material A and y kilograms of material B, is x >y?

Given: x+y=10. Question: is x>y?

(1) y > 4. Clearly insufficient: if y=4.5<x=5.5 the answer will be YES but if y=6>x=4 the answer will be NO.

(2) The cost of the 10 kilograms of material K is less than $40 ---> 3x+5y<40, as y=10-x then: 3x+5(10-x)<40 --> 2x>10 --> x>5, so x>y. Sufficient.

Answer: B.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 132595 [11], given: 12326

3 KUDOS received
Intern
Intern
User avatar
Joined: 21 Feb 2011
Posts: 1

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

Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 10 Mar 2011, 05:42
3
This post received
KUDOS
Material A cost 3$/kg and B cost 5$/kg.
If 10 kg of material K consist of x kg of A and y kg of B, is x>y?

1- y>4

2- the cost of 10kg of K is less than $40.

Solution: -

1) Insufficient
Material A cost 3$/kg and B cost 5$/kg
x+y=10 and y>4 is all we have from statement 1. Since the total price is not fixed, (x,y) can be anything satisfying x+y=10 ....even (5,5) can't be wrong in this case

2) Sufficient
Material A cost 3$/kg and B cost 5$/kg
x+y=10 and the cost of 10kg of K is less than $40.
Therefore, 3x+5y<40 => 3x+(10-x)5<40 => 10<2x => 5<x
So, x>5 and x+y=10 means x>y

Hope it helps !!!
_________________

Set out each day believing in your dreams.
Know without a doubt that you were made for amazing things.

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

3 KUDOS received
Director
Director
avatar
Status: Impossible is not a fact. It's an opinion. It's a dare. Impossible is nothing.
Affiliations: University of Chicago Booth School of Business
Joined: 03 Feb 2011
Posts: 871

Kudos [?]: 399 [3], given: 123

Reviews Badge
Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 10 Mar 2011, 07:22
3
This post received
KUDOS
x = 10 - y
Rephrasing the question - Is x > y?
or Is 10 - y > y
Is y < 5 ?

1. Insufficient
2. Sufficient
3x + 5y < 40
3(10 - y) + 4y < 40
2y < 10
Hence y < 5

Hence B.
alltimeacheiver wrote:
Material A costs $3 per kilogram, and material B costs $5 per kilogram. If 10 kilograms
of material K consists of x kilograms of material A and y kilograms of material B, is x >
y?
(1) y > 4
(2) The cost of the 10 kilograms of material K is less than $40

Kudos [?]: 399 [3], given: 123

5 KUDOS received
Manager
Manager
User avatar
Status: Employed
Joined: 17 Nov 2011
Posts: 98

Kudos [?]: 166 [5], given: 10

Location: Pakistan
Concentration: International Business, Marketing
GMAT 1: 720 Q49 V40
GPA: 3.2
WE: Business Development (Internet and New Media)
Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 16 Feb 2012, 08:47
5
This post received
KUDOS
1
This post was
BOOKMARKED
The answer has to be B.

Let's setup the weighted average equation for this question:

\(x\) kilograms at 3$ per Kilogram
\(y\) kilograms at 5$ per Kilogram
Yields \(10\) kilograms at z$ per Kilogram
We also know that \(x+y=10\)
So Equation would be : \(3(x)+5(y)=10(z)\)

Now let's look at the statements:

Statement 1: \(y>4\)

Remember: \(x+y=10\)
So: \(x\) could range between 0 and 6. Insufficient

Statement 2: Cost is \(<40\)

So \(3(x)+5(y)<40\)
But \(x+y=10\) so \(x=10-y\)
So \(3(10-y)+5(y)<40\)
So \(30-2y+5y<40\)
So \(2y<10\)
So \(y<5\)

If \(y<5\) then \(x>5\) so \(x>y\) Sufficient

Hence B
_________________

"Nowadays, people know the price of everything, and the value of nothing." Oscar Wilde

Kudos [?]: 166 [5], given: 10

Expert Post
2 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42249

Kudos [?]: 132595 [2], given: 12326

Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 13 Jun 2013, 02:15
2
This post received
KUDOS
Expert's post
Bumping for review and further discussion*. Get a kudos point for an alternative solution!

*New project from GMAT Club!!! Check HERE

All DS Mixture Problems to practice: search.php?search_id=tag&tag_id=43
All PS Mixture Problems to practice: search.php?search_id=tag&tag_id=114

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 132595 [2], given: 12326

2 KUDOS received
Director
Director
User avatar
Joined: 25 Apr 2012
Posts: 722

Kudos [?]: 865 [2], given: 724

Location: India
GPA: 3.21
WE: Business Development (Other)
Premium Member Reviews Badge
Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 15 Jun 2013, 14:13
2
This post received
KUDOS
alltimeacheiver wrote:
Material A costs $3 per kilogram, and Material B costs $5 per kilogram. If 10 kilograms of Material K consists of x kilograms of Material A and y kilograms of Material B, is x > y ?

(1) y > 4
(2) The cost of the 10 kilograms of Material K is less than $40.



Material K cost "C" can be found out by calculating

C= (3*x+5*y)/10

Now the cost C will be close to Material A cost if x is more than y and vice versa

from St 1 we have y>4
For eg y=5, x=5 Cost of Material K will be $4/kg (in between price of Material A and Material B)
now if x=4,y=6 ,Cost of material K will be be $ 4.2/kg
if x=1,y=9 then Cost of material will be 4.8$ per kg
but if we take y=4 and x=6 we get cost of material K as $ 3.8 per kg less than $ 4 which would have been the price had both material A and B were added equally.

Therefore if x>y we should have price of Material K < $ 4kg

Hence St1 alone not sufficient as we can have x=y or x<y

St 2, The cost of the 10 kilograms of Material K is less than $40.[/quote]

Cost of Material per kg <$4 which meets our above requirement which means x>y

Therefore ans st B
_________________


“If you can't fly then run, if you can't run then walk, if you can't walk then crawl, but whatever you do you have to keep moving forward.”

Kudos [?]: 865 [2], given: 724

Manager
Manager
avatar
B
Joined: 26 Jan 2015
Posts: 94

Kudos [?]: 13 [0], given: 112

Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 28 Nov 2015, 04:50
Bunuel wrote:
alltimeacheiver wrote:
Material A costs $3 per kilogram, and material B costs $5 per kilogram. If 10 kilograms of material K consists of x kilograms of material A and y kilograms of material B, is x >y?

(1) y > 4
(2) The cost of the 10 kilograms of material K is less than $40


Material A costs $3 per kilogram, and material B costs $5 per kilogram. If 10 kilograms of material K consists of x kilograms of material A and y kilograms of material B, is x >y?

Given: x+y=10. Question: is x>y?

(1) y > 4. Clearly insufficient: if y=4.5<x=5.5 the answer will be YES but if y=6>x=4 the answer will be NO.

(2) The cost of the 10 kilograms of material K is less than $40 ---> 3x+5y<40, as y=10-x then: 3x+5(10-x)<40 --> 2x>10 --> x>5, so x>y. Sufficient.

Answer: B.


Hi...If in the question it is mentioned that x and y are integers, then will the answer be D? because it will lead to contradiction that 'x is not greater than y' or will still answer be b because (there is no clarity whether x may be equal to y or may be less than y'?
_________________

Kudos is the best way to say Thank you! Please give me a kudos if you like my post

Kudos [?]: 13 [0], given: 112

Expert Post
2 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42249

Kudos [?]: 132595 [2], given: 12326

Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 28 Nov 2015, 07:59
2
This post received
KUDOS
Expert's post
Alok322 wrote:
Bunuel wrote:
alltimeacheiver wrote:
Material A costs $3 per kilogram, and material B costs $5 per kilogram. If 10 kilograms of material K consists of x kilograms of material A and y kilograms of material B, is x >y?

(1) y > 4
(2) The cost of the 10 kilograms of material K is less than $40


Material A costs $3 per kilogram, and material B costs $5 per kilogram. If 10 kilograms of material K consists of x kilograms of material A and y kilograms of material B, is x >y?

Given: x+y=10. Question: is x>y?

(1) y > 4. Clearly insufficient: if y=4.5<x=5.5 the answer will be YES but if y=6>x=4 the answer will be NO.

(2) The cost of the 10 kilograms of material K is less than $40 ---> 3x+5y<40, as y=10-x then: 3x+5(10-x)<40 --> 2x>10 --> x>5, so x>y. Sufficient.

Answer: B.


Hi...If in the question it is mentioned that x and y are integers, then will the answer be D? because it will lead to contradiction that 'x is not greater than y' or will still answer be b because (there is no clarity whether x may be equal to y or may be less than y'?


If we were told that x and y are integers then y > 4 (5, 6, 7, ...) together with x + y = 10, would be sufficient to say that x is NOT greater than y. But in this case the question would be flawed because the statements would contradict each other which never happens in proper GMAT DS questions.

Hope it's clear.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 132595 [2], given: 12326

Intern
Intern
avatar
Joined: 02 Oct 2014
Posts: 8

Kudos [?]: 1 [0], given: 10

Reviews Badge
Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 23 Dec 2015, 07:42
Thank you Buennel!

Very important point since i came here with the same problem and i pulled my hair over this for a solid 20 minutes.

If you simplify (2) it results in y < 5. While (1) says that y > 4.

Contradicting? No. We might think its contradictory if we assume that the qty involved are integers (common mistake, since qty usually are).

Do note that the question does not say that x or y are integers. And it is for this reason, otherwise, the question would logically be incorrect.

My takeaway:
1) Always remember that GMAT statements are never contradictory
2) If at some point, it seems like they are contradicting, it could mean
a) i've done it incorrectly
b) they aren't contradicting in the first place! :p
3) In such WP questions, ask yourself, are the quantities divisible into decimals?

Kudos [?]: 1 [0], given: 10

Expert Post
1 KUDOS received
Veritas Prep GMAT Instructor
User avatar
G
Joined: 16 Oct 2010
Posts: 7736

Kudos [?]: 17779 [1], given: 235

Location: Pune, India
Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 16 Mar 2016, 07:35
1
This post received
KUDOS
Expert's post
alltimeacheiver wrote:
Material A costs $3 per kilogram, and Material B costs $5 per kilogram. If 10 kilograms of Material K consists of x kilograms of Material A and y kilograms of Material B, is x > y ?

(1) y > 4
(2) The cost of the 10 kilograms of Material K is less than $40.


Responding to a pm:

Quote:
In solving the B part of this question (like in many situation i have faced) 3[5]+5[5]=15+25="40<40"
This is my question:
[Q-1] Can we ever take 40<40 ie x<x when x is same number. Similarly x>x and so on in GMAT?



To be honest, I am not sure what your question means.
40 < 40 is not correct and neither is x < x since both are equal.
And no, x > x doesn't work either.
If they are the same number, one cannot be greater than the other. You might want to show me the steps of where you come across this problem.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for $199

Veritas Prep Reviews

Kudos [?]: 17779 [1], given: 235

Intern
Intern
avatar
Joined: 30 Apr 2015
Posts: 7

Kudos [?]: [0], given: 19

Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 17 Dec 2016, 11:31
Bunuel wrote:
alltimeacheiver wrote:
Material A costs $3 per kilogram, and material B costs $5 per kilogram. If 10 kilograms of material K consists of x kilograms of material A and y kilograms of material B, is x >y?

(1) y > 4
(2) The cost of the 10 kilograms of material K is less than $40


Material A costs $3 per kilogram, and material B costs $5 per kilogram. If 10 kilograms of material K consists of x kilograms of material A and y kilograms of material B, is x >y?

Given: x+y=10. Question: is x>y?

(1) y > 4. Clearly insufficient: if y=4.5<x=5.5 the answer will be YES but if y=6>x=4 the answer will be NO.

(2) The cost of the 10 kilograms of material K is less than $40 ---> 3x+5y<40, as y=10-x then: 3x+5(10-x)<40 --> 2x>10 --> x>5, so x>y. Sufficient.

Answer: B.


Hi Bunuel,

Can this be solve via weighted average?
By the formulae n1/n2= (m2-m)/(m-m1)

Kudos [?]: [0], given: 19

Intern
Intern
avatar
B
Joined: 26 Oct 2016
Posts: 6

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

Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 08 Jan 2017, 18:51
I thought about this conceptually. Since A costs $3 per kg and B costs $5 per kg, I used that in conjunction with statement 2 to prove sufficiency. In statement 2, 10kg of K is less than $40. Dividing both sides by 10, 1 kg of K is less than $4. Knowing the costs of X and Y, that to me would mean that there would have to be more of A than B to be less than $4 (equal amounts would have it equal $4).

It's not perfect as we could be dealing with integers and you can't assume one of A or B isn't 0....but it's how I went about it.

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

Intern
Intern
avatar
Joined: 29 Mar 2017
Posts: 3

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

Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 05 Apr 2017, 10:35
I have a question,

the question provide 10=x+y, it's about the weight

but it doesn't mean 3x+5y<40 (money), cuz 40=10k, we don't know the unit price of k, so i don't think it's right.

Is there anything wrong of me? I was confused a litte...hehe

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

Moderator
avatar
D
Joined: 22 Jun 2014
Posts: 939

Kudos [?]: 464 [0], given: 113

Location: India
Concentration: General Management, Technology
GMAT 1: 540 Q45 V20
GPA: 2.49
WE: Information Technology (Computer Software)
Premium Member CAT Tests
Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 05 Apr 2017, 11:34
dxhzhu wrote:
I have a question,

the question provide 10=x+y, it's about the weight

but it doesn't mean 3x+5y<40 (money), cuz 40=10k, we don't know the unit price of k, so i don't think it's right.

Is there anything wrong of me? I was confused a litte...hehe


x + y = 10 ---equation (1)

from stmt-2 we can say 3x + 5y < 40

multiply equation (1) by 3 and you get 3x + 3y = 30

3x + 5y < 40 (to subtract the below equation, consider < as = sign)
3x + 3y = 30

2y < 10 (isnt it? because if you subtract 30 from somthing less than 40 then you get something less than 10)

hence y < 5, it means x > y because x + y = 10

so B is correct. Hope your doubt is clear.
_________________

---------------------------------------------------------------
Target - 720-740
http://gmatclub.com/forum/information-on-new-gmat-esr-report-beta-221111.html
http://gmatclub.com/forum/list-of-one-year-full-time-mba-programs-222103.html

Kudos [?]: 464 [0], given: 113

Intern
Intern
avatar
B
Joined: 30 Mar 2017
Posts: 10

Kudos [?]: 0 [0], given: 17

Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 05 Aug 2017, 00:13
We can work this out using weighted average method as well.

Statement A: y>4 - clearly insufficient.

Statement B: Cost of 10kg of Material K is less than $40.

Cost of A is $3/kg and of B is $5/kg. Average cost of 10 kgs of combined material is <$4 ($40/10kgs). Using weighted average method:

3------------------------5
l------------4
Weighted average is less than 4, which means ratio of quantity of A:B i.e. x:y is skewed towards A. Thus, x>y.

Kudos [?]: 0 [0], given: 17

Senior Manager
Senior Manager
User avatar
G
Joined: 29 Jun 2017
Posts: 367

Kudos [?]: 70 [0], given: 66

GPA: 4
WE: Engineering (Transportation)
GMAT ToolKit User Reviews Badge
Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 17 Aug 2017, 03:23
1) A 3$.
B 5$.

x+y =10
x. 5 4 3
y. 5 6 7

x=y and x<y. Insufficient A,D gone

2) A 3 $ and B 5 $
suppose all material is A then cost will be 30 $ when x=10
suppose all material is B then cost will be 50 $ when y = 10
and when x=y=5 equal the cost is 40 $

now since it is given that cost < 40$ means proportion of A is more than B

x>y clearly B is sufficient

B is answer
_________________

Give Kudos for correct answer and/or if you like the solution.

Kudos [?]: 70 [0], given: 66

Manager
Manager
avatar
S
Joined: 13 Mar 2013
Posts: 179

Kudos [?]: 75 [0], given: 25

Location: United States
Concentration: Leadership, Technology
GPA: 3.5
WE: Engineering (Telecommunications)
Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 17 Aug 2017, 09:44
1) Insufficient
Material A cost 3$/kg and B cost 5$/kg
x+y=10 and y>4 is all we have from statement 1. Since the total price is not fixed, (x,y) can be anything satisfying x+y=10 ....even (5,5) can't be wrong in this case

2) Sufficient
Material A cost 3$/kg and B cost 5$/kg
x+y=10 and the cost of 10kg of K is less than $40.
Therefore, 3x+5y<40 => 3x+(10-x)5<40 => 10<2x => 5<x
So, x>5 and x+y=10 means x>y
_________________

Regards ,

Kudos [?]: 75 [0], given: 25

Manager
Manager
avatar
B
Joined: 19 Mar 2015
Posts: 59

Kudos [?]: 11 [0], given: 26

Location: India
Concentration: Marketing, International Business
Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 19 Aug 2017, 01:03
Very nice Question ... I got it wrong because I didn't calculated statement 2 fully.
I have come down to below points:
3x+7Y<40, 4x+6Y<40 and so on but I didn't solve without knowing that all will give the solution x>5.
and as x+y is 10, x must be 6 and here we get the answer.

Kudos to the question.

Kudos [?]: 11 [0], given: 26

Senior Manager
Senior Manager
User avatar
G
Joined: 19 Oct 2012
Posts: 335

Kudos [?]: 54 [0], given: 103

Location: India
Concentration: General Management, Operations
GMAT 1: 660 Q47 V35
GMAT 2: 710 Q50 V38
GPA: 3.81
WE: Information Technology (Computer Software)
CAT Tests
Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram [#permalink]

Show Tags

New post 29 Aug 2017, 12:13
alltimeacheiver wrote:
Material A costs $3 per kilogram, and Material B costs $5 per kilogram. If 10 kilograms of Material K consists of x kilograms of Material A and y kilograms of Material B, is x > y ?

(1) y > 4
(2) The cost of the 10 kilograms of Material K is less than $40.


The question can solved using weighted average concept easily without pen and paper calculation i.e can be solved within 30 seconds.

10kg of mixture uses x kg of Material A and y kg of Material B. If both X and Y are equal, the cost of the 10kg of material K will be right in the middle of $30 and $50 i.e. at $40.

But using stmt B, 10kg of K costs less than $40 dollars i.e. the cost shift towards $30. Hence clearly the quantity of X is more and Y. Hence B is sufficient.

I hope that helps.
_________________

Citius, Altius, Fortius

Kudos [?]: 54 [0], given: 103

Re: Material A costs $3 per kilogram, and Material B costs $5 per kilogram   [#permalink] 29 Aug 2017, 12:13

Go to page    1   2    Next  [ 21 posts ] 

Display posts from previous: Sort by

Material A costs $3 per kilogram, and Material B costs $5 per kilogram

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

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

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®.