Author 
Message 
TAGS:

Hide Tags

Director
Joined: 25 Oct 2008
Posts: 596
Location: Kolkata,India

Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
13 Aug 2009, 15:55
1
This post received KUDOS
10
This post was BOOKMARKED
Question Stats:
62% (02:05) correct
38% (01:30) wrong based on 354 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.
Official Answer and Stats are available only to registered users. Register/ Login.
_________________
http://gmatclub.com/forum/countdownbeginshasended8548340.html#p649902
Last edited by Bunuel on 13 Oct 2014, 07:40, edited 4 times in total.
Edited the question and added the OA



Manager
Joined: 25 Jul 2009
Posts: 116
Schools: NYU, NUS, ISB, DUKE, ROSS, DARDEN

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
13 Aug 2009, 16:10
tejal777 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.
umm...(D) is it?? Yeah...its D. St1: if y>4, then x =< 5 => x =< y => SUFFICIENTSt2: If 10 kg of material k cost $40, then x = y = 5 But if it costs less than $40 then y < 5 => x > 5 => SUFFICIENTANS: D
_________________
KUDOS me if I deserve it !!
My GMAT Debrief  740 (Q50, V39)  My TestTaking Strategies for GMAT  Sameer's SC Notes



SVP
Joined: 29 Aug 2007
Posts: 2473

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
13 Aug 2009, 21:49
What if x = 4.9 kgs and y = 4.1 kgs? How do you know that material k consists materials A and B only in whole kgs? B is not a big deal. samrus98 wrote: tejal777 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.
umm...(D) is it?? Yeah...its D. St1: if y>4, then x =< 5 => x =< y => SUFFICIENTSt2: If 10 kg of material k cost $40, then x = y = 5 But if it costs less than $40 then y < 5 => x > 5 => SUFFICIENTANS: D
_________________
Verbal: http://gmatclub.com/forum/newtotheverbalforumpleasereadthisfirst77546.html Math: http://gmatclub.com/forum/newtothemathforumpleasereadthisfirst77764.html Gmat: http://gmatclub.com/forum/everythingyouneedtoprepareforthegmatrevised77983.html
GT



Manager
Joined: 25 Jul 2009
Posts: 116
Schools: NYU, NUS, ISB, DUKE, ROSS, DARDEN

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
14 Aug 2009, 04:14
1
This post received KUDOS
yezz wrote: samrus98 wrote: tejal777 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.
umm...(D) is it?? Yeah...its D. St1: if y>4, then x =< 5 => x =< y => SUFFICIENTSt2: If 10 kg of material k cost $40, then x = y = 5 But if it costs less than $40 then y < 5 => x > 5 => SUFFICIENTANS: DCan you plz explain why we are excluding non intiger values for x,y? thanks Its a mistake. X & Y can take noninteger values as well and that makes St1 insufficient. Revised ANS: B
_________________
KUDOS me if I deserve it !!
My GMAT Debrief  740 (Q50, V39)  My TestTaking Strategies for GMAT  Sameer's SC Notes



Manager
Joined: 10 Jul 2009
Posts: 126
Location: Ukraine, Kyiv

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
17 Sep 2009, 11:13
B. couple of examples: x=4, y=6, sum>40. not satisfies x=5, y=5, sum =40. not satisfies x=6, y=4, sum<40. satisfiesnonintegers should be taken into account as well. However, they all satisfy this.
_________________
Never, never, never give up



Manager
Joined: 21 Jul 2009
Posts: 249
Location: New York, NY

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
23 Sep 2009, 15:53
x=3, y=6 <40 x=8, y=3 <40
B is not sufficient.
Am I missing something?



Intern
Joined: 18 Sep 2009
Posts: 19

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
24 Sep 2009, 09:51
tejal777 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.
umm...(D) is it?? Hi, From the stem we have: X (MAT A) + Y (MAT B) =10 (i) and 3X+5Y=TOTAL COST. (II) FOR (1): Y>4. Y=4,1 and X=5,9 OR Y=6 and X=4 (INSUFFI) FOR (2): 3X+5Y<40 ; 40*(I) => 40X+40Y=40 ; We have that 3x+5y< 40X+40Y => 37x<35y; Again (X+Y=10)=> X=6,Y=4 or X=4,Y=6 We dont know really. (INSUFFI) FOR (1) and (2) => The same, we dont any more information! FOR THIS, IMO (E)



Director
Joined: 25 Oct 2008
Posts: 596
Location: Kolkata,India

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
20 Oct 2009, 00:57
Came back to the question again:( Quote: 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. OE says: Since x + y = 10, the relation x > y is equivalent to x > 10 – x, or x > 5.(1) The given information is consistent with x = 5.5 and y = 4.5, and the given information is also consistent with x = y = 5.Therefore, it is possible for x > y to be true and it is possible for x > y to be false; NOT sufficient. How can we take the case of x = y = 5 when we know x>5??
_________________
http://gmatclub.com/forum/countdownbeginshasended8548340.html#p649902



CEO
Status: Nothing comes easy: neither do I want.
Joined: 12 Oct 2009
Posts: 2783
Location: Malaysia
Concentration: Technology, Entrepreneurship
GMAT 1: 670 Q49 V31 GMAT 2: 710 Q50 V35

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
20 Oct 2009, 02:48
1
This post received KUDOS
X + Y = 10 3X + 5Y < 40 Now 3X + 5Y = 3( X + Y ) + 2Y = 30 + 2Y < 40 => 2Y < 10 => Y < 5 that means x must be > 5 . Now to check whether if X > Y can be solved if we can find the range of Y then we can check whether X >y or not as both will sum up to 10. Since equation 1 and 2 both give the range of Y...thus both are individually sufficient. Ans is D , OA pls
_________________
Fight for your dreams :For all those who fear from Verbal lets give it a fight
Money Saved is the Money Earned
Jo Bole So Nihaal , Sat Shri Akaal
Support GMAT Club by putting a GMAT Club badge on your blog/Facebook
GMAT Club Premium Membership  big benefits and savings
Gmat test review : http://gmatclub.com/forum/670to710alongjourneywithoutdestinationstillhappy141642.html



CEO
Status: Nothing comes easy: neither do I want.
Joined: 12 Oct 2009
Posts: 2783
Location: Malaysia
Concentration: Technology, Entrepreneurship
GMAT 1: 670 Q49 V31 GMAT 2: 710 Q50 V35

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
20 Oct 2009, 03:05
Oh yea Ans is B as if y >4 y = 10x > 4 ==> 6 > x thus its not sufficient....
_________________
Fight for your dreams :For all those who fear from Verbal lets give it a fight
Money Saved is the Money Earned
Jo Bole So Nihaal , Sat Shri Akaal
Support GMAT Club by putting a GMAT Club badge on your blog/Facebook
GMAT Club Premium Membership  big benefits and savings
Gmat test review : http://gmatclub.com/forum/670to710alongjourneywithoutdestinationstillhappy141642.html



Manager
Joined: 10 Sep 2009
Posts: 112

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
20 Oct 2009, 08:19
for me it's A
1) y > 4 => y >= 5
y = 5 x = 5 => x = y y = 6 x = 4 => x < y
in both case x is not > y
2) 3x + 5(10  x) <= 40
=> x >= 5
x = 5 y = 5 x = 6 y = 4
=> x >=y so it is not sufficient
ans is then A
what is OA?
EDIT
Dam it' !!! less than 40 means < 40... B is then suffiscient too



CEO
Status: Nothing comes easy: neither do I want.
Joined: 12 Oct 2009
Posts: 2783
Location: Malaysia
Concentration: Technology, Entrepreneurship
GMAT 1: 670 Q49 V31 GMAT 2: 710 Q50 V35

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
20 Oct 2009, 08:28
1
This post was BOOKMARKED
pierrealexandre77 wrote: for me it's A
1) y > 4 => y >= 5
y = 5 x = 5 => x = y y = 6 x = 4 => x < y
in both case x is not > y
2) 3x + 5(10  x) <= 40
=> x >= 5
x = 5 y = 5 x = 6 y = 4
=> x >=y so it is not sufficient
ans is then A
what is OA?
EDIT
Dam it' !!! less than 40 means < 40... B is then suffiscient too Its not given X n Y are integers , thus first condition is not sufficient
_________________
Fight for your dreams :For all those who fear from Verbal lets give it a fight
Money Saved is the Money Earned
Jo Bole So Nihaal , Sat Shri Akaal
Support GMAT Club by putting a GMAT Club badge on your blog/Facebook
GMAT Club Premium Membership  big benefits and savings
Gmat test review : http://gmatclub.com/forum/670to710alongjourneywithoutdestinationstillhappy141642.html



Manager
Joined: 13 Oct 2009
Posts: 55
Location: New York, NY
Schools: Columbia, Johnson, Tuck, Stern

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
21 Oct 2009, 07:14
4
This post received KUDOS
I think i got a simplier explanation:
x + y = 10 1) y>4 : Y can be anything 4.2, 4.7, 6, 7. In this case, we can't determine if X is greater than 5.
2) Total cost of K is less than 40:
3x + 5y < 40 x + y = 10 > x = 10  y
3(10  y) + 5y < 40 30  3y + 5y < 40 2y < 10 y < 5
Since y is less than 5, we know that it can be 4.9 so X is greater than Y. B



Manager
Joined: 22 Mar 2009
Posts: 77
Schools: Darden:Tepper:UCUIC:Kenan Flager:Nanyang:NUS:ISB:UCI Merage:Emory
WE 1: 3

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
23 Oct 2009, 05:11
mendelay wrote: x=3, y=6 <40 x=8, y=3 <40
B is not sufficient.
Am I missing something? Hi mendelay... ur mising the condition X+ Y = 10. so ur assumptions of x =3 and y =6 wont work out .so does 8 and 3.
_________________
Second cut is the deepest cut!!!:P



Retired Moderator
Status: The last round
Joined: 18 Jun 2009
Posts: 1296
Concentration: Strategy, General Management

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
06 Dec 2009, 10:18
Material A cost 3$/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.
_________________
[ From 470 to 680My Story ] [ My Last Month Before Test ] [ GMAT Prep Analysis Tool ] [ US. Business School Dashboard ] [ Int. Business School Dashboard ]
I Can, I Will
GMAT Club Premium Membership  big benefits and savings



Senior Manager
Joined: 30 Aug 2009
Posts: 287
Location: India
Concentration: General Management

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
06 Dec 2009, 10:41
Hussain15 wrote: Material A cost 3$/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. B 1. insuff as y can be any value from 4.1kg to 9.9kg 2. cost of K per kg is less than $4 which means A will be more. hence suff



Retired Moderator
Status: The last round
Joined: 18 Jun 2009
Posts: 1296
Concentration: Strategy, General Management

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
06 Dec 2009, 10:45
kp1811 wrote: 2.cost of K per kg is less than $4 which means A will be more. hence suff I didn't get this one. Can you kindly explain in detail?
_________________
[ From 470 to 680My Story ] [ My Last Month Before Test ] [ GMAT Prep Analysis Tool ] [ US. Business School Dashboard ] [ Int. Business School Dashboard ]
I Can, I Will
GMAT Club Premium Membership  big benefits and savings



Senior Manager
Joined: 30 Aug 2009
Posts: 287
Location: India
Concentration: General Management

Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
Show Tags
06 Dec 2009, 10:58
Hussain15 wrote: kp1811 wrote: 2.cost of K per kg is less than $4 which means A will be more. hence suff I didn't get this one. Can you kindly explain in detail? lets consider the below cases if x and y are equal i.e. 5kg then avg price of K will be = x* price of A + y* price of B = (5* 3 + 5*5)/10 = $4/kg. now let x be 4kg then y is 6kg so avg price will be = (4* 3 + 6*5)/10 = $4.2/kg if x is 6kg then y is 4kg then avg price will be ( 6*3+ 4*5)/10 = $3.8/kg so we can see that only if x>y then cost of K will be less than $4 note: avg price of K is same as cost of K



Manager
Joined: 06 Apr 2010
Posts: 146

Material A costs $3 per kilogram, and material B costs $5 per kilogram [#permalink]
Show Tags
12 Sep 2010, 07:24
1
This post received KUDOS
5
This post was BOOKMARKED
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.



Intern
Joined: 18 Jul 2010
Posts: 47

Re: Material A costs $3 per kilogram, and material B costs $5 per kilogram [#permalink]
Show Tags
12 Sep 2010, 08:02
1
This post received KUDOS
3
This post was BOOKMARKED
We lnow first that x + y = 10.
(1) if y > 4 so we can have y = 4.5 kg and x = 5.5 kg (so y<x) or the oppositive : y = 5.5 kg and x = 4.5 kg (so x<y). INSUFFICIENT
(2) we knows that 3x + 5y < 40 (1) . But we also know that x + y = 10 <=> 3x+3y = 30 (2). By doing (2)  1 we obtain 2y < 10 <=> y < 5kg. So, as x + y = 10, x > 5kg.
Thus, x > y. SUFFICIENT.
Answer : B.
Last edited by alexn49 on 12 Sep 2010, 09:36, edited 1 time in total.




Re: Material A costs $3 per kilogram, and material B costs $5 per kilogram
[#permalink]
12 Sep 2010, 08:02



Go to page
1 2 3
Next
[ 41 posts ]




