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Re: Material A costs $3 per kilogram, and material B costs $5 per kilogram [#permalink]
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21 Sep 2010, 11:33
udaymathapati 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. I did it slightly differently. We know x + y = 10... (1) Clearly insufficient. (2) If x = y = 5, then the 10kg of material K costs ($3*5) + ($5*5) = $40. Since x costs less than y, the more you increase x, the less material K will cost. So if K costs less than $40, x must be greater than 5, and so y is less than 5. Sufficient.



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Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
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22 Apr 2011, 23:27
answer is B question simplifies to x+y=10 is x>y 1. y >4 is x> y so we have y=4.5 then x= 5.5 yes y= 5 then x= 5 no y= 6 then x=4 no in sufficent 2. gives 3x+5y<40 and x,y>0 so we have 3(10y) +5y < 40 y<5 now for all values of y<5 === x> y since x+y=10 hence B
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Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
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22 Apr 2011, 23:50
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?? (1) y>4 y=4.1kg; x=4.2kg x=4.2kg; y=4.2kg Not Sufficient. (2) y=1kg; x=2kg; cost=2*3+1*5=11<40 y=2kg; x=1kg; cost=2*1+2*5=12<40 Not Sufficient. Combining both: y=4.5;x=5; cost=5*3+4.5*5=15+22.5=37.5<40 y=5;x=1; cost=1*3+5*5=3+25=28<40 Not Sufficient. Ans:"E" P.S.: It is not given that material k contains ONLY material A and B. Had it been given, "B" alone would have sufficed.
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Re: Material A costs $3 per kilogram, and material B costs $5 per kilogram [#permalink]
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22 Apr 2011, 23:57
answer is D remember x+y=10 in question statement
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Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
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23 Apr 2011, 02:54
fluke 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?? (1) y>4 y=4.1kg; x=4.2kg x=4.2kg; y=4.2kg Not Sufficient. (2) y=1kg; x=2kg; cost=2*3+1*5=11<40 y=2kg; x=1kg; cost=2*1+2*5=12<40 Not Sufficient. Combining both: y=4.5;x=5; cost=5*3+4.5*5=15+22.5=37.5<40 y=5;x=1; cost=1*3+5*5=3+25=28<40 Not Sufficient. Ans:"E" P.S.: It is not given that material k contains ONLY material A and B. Had it been given, "B" alone would have sufficed. if it says item k consist of A and B i hope it means it consists of a and b only otherwise so many GMAT would have answer as E this question will too simple to answer if assume what you are saying AM i correct
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Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
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23 Apr 2011, 03:20
kamalkicks wrote: if it says item k consist of A and B i hope it means it consists of a and b only otherwise so many GMAT would have answer as E
this question will too simple to answer if assume what you are saying
AM i correct My intention is not to debunk this question as many agree with the OA to be "B", making your interpretation correct . But it would definitely be less ambiguous if the author mentioned the fact explicitly, at least for me. I consider all of the three statements correct: Sulphuric Acid, \(H_2SO_4\), consists hydrogen and sulphur. Water, \(H_2O\), consists only hydrogen and oxygen. Water, \(H_2O\), consists hydrogen and oxygen.
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Re: Material A costs $3 per kilogram, and material B costs $5 per kilogram [#permalink]
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23 Apr 2011, 05:13
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The question can be rephrased as  x > y? Or (10  y) > y Or y < 5 ? Is y < 5 ?1. Insufficient. y can be 6 or y can be 4.5 2. 3x + 5y < 40 and we know that x = 10  y 3(10 y) + 5y < 40 30 3y + 5y < 40 2y < 10 y < 5 Sufficient Answer B udaymathapati 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.



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Re: Material A costs $3 per kilogram, and material B costs $5 per kilogram [#permalink]
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23 Apr 2011, 07:26
x+y = 10
x>y? 10y>y => y<5?
1. Insufficient y>4 doesnt mean y <5.
y = 4.5 <5 y = 5 is not less than 5
2. Sufficient
3x+5y <40
=> 3(10y)+5y <40 => y <5
Answer is B.



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Re: Material A costs $3 per kilogram, and material B costs $5 per kilogram [#permalink]
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23 Apr 2011, 07:58
Statement 1  Not possible to get any single answer as y could be 4.5 or even 5.5 Statement 2  If x=y, then the cost of 10 kgs would be 40 If it is less than 40 means that quantity of y (higher priced item) is less than X (lower priced)
So with statement B, a unique solution can be derived
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Re: Material A costs $3 per kilogram, and material B costs $5 per kilogram [#permalink]
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24 Apr 2011, 07:36
3x + 5y x + y = 10 (1) y > 4 But x = 5, y = 5 is possible y = 4.5 x = 5.5 is possible (2) 3x + 5y < 40 3(10  y) + 5y < 40 2y < 10 y < 5 So x > y  sufficient Answer  B
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Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
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24 Apr 2011, 07:39
3x + 5y x + y = 10 (1) y > 4 But x = 5, y = 5 is possible y = 4.5 x = 5.5 is possible (2) 3x + 5y < 40 3(10  y) + 5y < 40 2y < 10 y < 5 So x > y  sufficient Answer  B
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Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
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24 Apr 2011, 08:11
1. Not sufficient
y > 4
y 6 4.5 x 4 5.5
x<y x>y
2. Sufficient 3x +5y <40
303y+5y <40 y<5
y 4.5 4
x 5.5 6
x>y x>y
Answer is B.



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Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
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24 Apr 2011, 11:52
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fluke 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?? (1) y>4 y=4.1kg; x=4.2kg x=4.2kg; y=4.2kg Not Sufficient. (2) y=1kg; x=2kg; cost=2*3+1*5=11<40 y=2kg; x=1kg; cost=2*1+2*5=12<40 Not Sufficient. Combining both: y=4.5;x=5; cost=5*3+4.5*5=15+22.5=37.5<40 y=5;x=1; cost=1*3+5*5=3+25=28<40 Not Sufficient. Ans:"E" P.S.: It is not given that material k contains ONLY material A and B. Had it been given, "B" alone would have sufficed. Dear Fluke now that we have that the total quantity is 10 kg so clearly y=10x so total cost of the mixture 3x+5(10x)=502x (1) y>4 i.e. 10x>4 so x<6 clearly there can be values of both x & y =5 so in this case x=y no sufficient (2) says 502x<40 so x>5 so by this we get y<5 so clearly y<x to make the cost less than 40 B is the answer please correct me
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Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
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25 Oct 2011, 07:01
fluke wrote: Warlock007 wrote: Dear Fluke now that we have that the total quantity is 10 kg so clearly y=10x so total cost of the mixture 3x+5(10x)=502x (1) y>4 i.e. 10x>4 so x<6 clearly there can be values of both x & y =5 so in this case x=y no sufficient (2) says 502x<40 so x>5 so by this we get y<5 so clearly y<x to make the cost less than 40 B is the answer please correct me You are correct. I just abortively tried to make a point. Fluke? why is the correct answer B? From your previous post I understood that it is E. I agree with your previous post where you said that it should have said "it consists of ONLY x and y..." to be correct. Could you please elaborate on that?



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Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
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25 Oct 2011, 09:56
SonyGmat wrote: Fluke? why is the correct answer B? From your previous post I understood that it is E.
I agree with your previous post where you said that it should have said "it consists of ONLY x and y..." to be correct.
Could you please elaborate on that? Precisely so. Answer should be "E" as per my interpretation of the wordings. I just surrendered halfheartedly to "B" :D I recommend you skip this question. GMAT's wordings will be very precise and without ambiguity.
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Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
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11 Dec 2011, 10:13



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Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
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16 Feb 2012, 08:08
tejal777 wrote: Ohh!! People this is why I bow down to this forum...Thank you..! Tejal: Please don't get bow down. The answere is E. Take 1st statement: X= 5.1 and Y= 4.9, here X>Y X= 5 and Y=5 X=Y X=4 and Y= 6 X<Y Hence 1 is not sufficient Take Statement 2: 3X+4Y< 40 Lets take X=6 and Y=4 total cost = 34<40 Take x= 4 and Y= 6 Total Cost= 38<40 Cannot determined x and y,henec not sufficient Combine both: Y=5,X=5 3X+4Y= 33<40 Y= 4.1 X= 5.9 3X+4Y= 34.1 <40 Not sufficient. Some of my friends have argued that there is nothing mentioned like mixture consists of only A and B. This factor would add further uncertainity. Hence E is the best answere according to me.



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Re: Material A costs $3 per kilogram, and material B costs $5 [#permalink]
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16 Feb 2012, 09:45
jaymin1986 wrote: tejal777 wrote: Ohh!! People this is why I bow down to this forum...Thank you..! Tejal: Please don't get bow down. The answere is E. Take 1st statement: X= 5.1 and Y= 4.9, here X>Y X= 5 and Y=5 X=Y X=4 and Y= 6 X<Y Hence 1 is not sufficient Take Statement 2: 3X+4Y< 40 Lets take X=6 and Y=4 total cost = 34<40 Take x= 4 and Y= 6 Total Cost= 38<40 Cannot determined x and y,henec not sufficient Combine both: Y=5,X=5 3X+4Y= 33<40 Y= 4.1 X= 5.9 3X+4Y= 34.1 <40 Not sufficient. Some of my friends have argued that there is nothing mentioned like mixture consists of only A and B. This factor would add further uncertainity. Hence E is the best answere according to me. The OA for this question is B, not E. Open discussion of the question is here: materialacosts3perkilogramandmaterialbcosts82349.htmlIn case of any question please continue discussion there.
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Re: Material A costs $3 per kilogram, and material B costs $5 per kilogram [#permalink]
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27 Nov 2014, 22:52
St1. INSUFFICIENT
St.2 means that mixture average cost is 40/10<4$/kg.
345
It is shifting to 3$ component, so x>y. SUFFICIENT
B




Re: Material A costs $3 per kilogram, and material B costs $5 per kilogram
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