Last year all refuse collected by Shelbyville city /services was incinerated. This incineration generated a large quantity of residual ash. In order to reduce the amount of residual ash Shelbyville generates this year to half of last year's total, the city has revamped its collection program. This year city services will separate for recycling enough refuse to reduce the number of truckloads of refuse to be incinerated to half of last year's number.
Which of the following is required for the revamped collection program to achieve its aim?
(A) This year, no materials that city services could separate for recycling will be incinerated.
(B) Separating recyclable materials from materials to be incinerated will cost Shelbyville less than half what it cost last year to dispose of the residual ash.
(C) Refuse collected by city services will contain a larger proportion of recyclable materials this year than it did last year.
(D) The refuse incinerated this year will generate no more residual ash per truckload incinerated than did the refuse incinerated last year.
(E) The total quantity of refuse collected by Shelbyville city service's this year will be no greater than that collected last year.
OA D
Why not C
for C
OG says that NO INFO on how much, if any , recyclable material were removed from the refus last year,
But then in OA too, we dont know how much if any refuse incinerated last year !
I am missing something here.,!!
ASH
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The plan is to reduce the number of truckloads of refuse to be incinerated to half.
D mentions exactly what we need, if the refuse incinerated will generate no more residual per truckload then the revamp program will achieve its aim.
Number of truckloads last year = 100
Number of truckloads this year = 50
refuse incinerated per truckload remains the same for both the years. Therefore, overall less residual ash will be generated this year.
D mentions exactly what we need, if the refuse incinerated will generate no more residual per truckload then the revamp program will achieve its aim.
Number of truckloads last year = 100
Number of truckloads this year = 50
refuse incinerated per truckload remains the same for both the years. Therefore, overall less residual ash will be generated this year.
mmslf75 wrote:Last year all refuse collected by Shelbyville city /services was incinerated. This incineration generated a large quantity of residual ash. In order to reduce the amount of residual ash Shelbyville generates this year to half of last year's total, the city has revamped its collection program. This year city services will separate for recycling enough refuse to reduce the number of truckloads of refuse to be incinerated to half of last year's number.
Which of the following is required for the revamped collection program to achieve its aim?
(D) The refuse incinerated this year will generate no more residual ash per truckload incinerated than did the refuse incinerated last year.
OA D
Why not C
for C
OG says that NO INFO on how much, if any , recyclable material were removed from the refus last year,
But then in OA too, we dont know how much if any refuse incinerated last year !
I am missing something here.,!!
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Hey let me explain the stimulus clearly,
City S sent 100 truck loads of refuse to be incinerated.
say the 100 truck loads of refuse led to 1000 kg of residual ash.
Now the city wants to reduce the amount of ash it produced last year (500 kg)
so how does it proceed to do this? by reducing the number of truck loads say 50.
wat is the inherent assumption in this plan?
The conversion of the truckload to residual ash remains the same.
for eg. in our case if 50 truck loads led to even greater proportion of residual ash say 1000 kg as opposed to 100 trucks leading to 1000 kg of ash, our conclusion falls apart. The program cannot be successful.
Our dear author makes this assumption that the conversion would be proportional.
This question is infact nicely worded assumption question. All u need to do here is find the assumption involved.
If u observe closely u will notice that this is a defender assumption, wherein the assumption protects the status quo of the passage.
following the above reasoning, in C, Even if a larger proportion of recyclable materials are segregated this year, if the proportional conversion of the refuse to ash not assumed, does this hold good?
That is the plain reason we eliminate C.
City S sent 100 truck loads of refuse to be incinerated.
say the 100 truck loads of refuse led to 1000 kg of residual ash.
Now the city wants to reduce the amount of ash it produced last year (500 kg)
so how does it proceed to do this? by reducing the number of truck loads say 50.
wat is the inherent assumption in this plan?
The conversion of the truckload to residual ash remains the same.
for eg. in our case if 50 truck loads led to even greater proportion of residual ash say 1000 kg as opposed to 100 trucks leading to 1000 kg of ash, our conclusion falls apart. The program cannot be successful.
Our dear author makes this assumption that the conversion would be proportional.
This question is infact nicely worded assumption question. All u need to do here is find the assumption involved.
If u observe closely u will notice that this is a defender assumption, wherein the assumption protects the status quo of the passage.
following the above reasoning, in C, Even if a larger proportion of recyclable materials are segregated this year, if the proportional conversion of the refuse to ash not assumed, does this hold good?
That is the plain reason we eliminate C.
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received a pm.
Both Vikas and Fibonacci explain very clearly why choice D is correct.
In terms of strategy: remember that wrong answer choices are nothing but distractions. Here, it is A LOT easier to see why choice D is correct than it is to articulate why choice C is incorrect.
If you got this question on test-day, the moment you see that choice D is clearly correct is the moment you should select it, hit the "confirm" button and go on the next question. Bluntly put: who gives a damn about why choice C is wrong?! POE is an inherently sub-optimal approach in CR for many reasons: articluating why wrong answers are wrong distracts us from the task we are rewarded for--announcing the correct answer; articulating why wrong answers are wrong takes up precious time; worrying about a particulalry tempting wrong answer may cause us to select it even though we may have reasoned that another choice was correct; etc.
Choice C is wrong because the plan definitely does not depend on there being a larger proportion of recycleable materials. In fact, the smaller the proportion of recycleable materials, the easier it will be to implement the plan! And, it simply does not matter that we don't know the proportion of recycleable materials in the previous year because the only way the previous year is significant is that it presents the problem (too much residual ash from incinerating recycleable materials), and helps us to understand the rationale of their solution.
Both Vikas and Fibonacci explain very clearly why choice D is correct.
In terms of strategy: remember that wrong answer choices are nothing but distractions. Here, it is A LOT easier to see why choice D is correct than it is to articulate why choice C is incorrect.
If you got this question on test-day, the moment you see that choice D is clearly correct is the moment you should select it, hit the "confirm" button and go on the next question. Bluntly put: who gives a damn about why choice C is wrong?! POE is an inherently sub-optimal approach in CR for many reasons: articluating why wrong answers are wrong distracts us from the task we are rewarded for--announcing the correct answer; articulating why wrong answers are wrong takes up precious time; worrying about a particulalry tempting wrong answer may cause us to select it even though we may have reasoned that another choice was correct; etc.
Choice C is wrong because the plan definitely does not depend on there being a larger proportion of recycleable materials. In fact, the smaller the proportion of recycleable materials, the easier it will be to implement the plan! And, it simply does not matter that we don't know the proportion of recycleable materials in the previous year because the only way the previous year is significant is that it presents the problem (too much residual ash from incinerating recycleable materials), and helps us to understand the rationale of their solution.
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TestLuv,
The approach you suggested to CR questions is opposite to what most instructors or even CR books tell us. When i first read the question i found 3 choices to be contenders.
A) If materials selected for recycling are incinerated, then they will add to the residual ash, and hence will be greater than half of residual ash last year... Agreed that it may seem a little far fledged, but since its option A, i'll keep it as a contender.
C) Now if City services contain larger proportion of recycle materials this year than last year, then residual ash will be lesser than last year.. .But in hindsight, there is no guarantee that it will half of last year...
D) Makes sense.. its at this point i get confused between A and D.
Though in hindsight, Trucks coming out of nowhere in the argument could have been an indicator that answer choice should address Truckloads.
Phew! Tough World.
The approach you suggested to CR questions is opposite to what most instructors or even CR books tell us. When i first read the question i found 3 choices to be contenders.
A) If materials selected for recycling are incinerated, then they will add to the residual ash, and hence will be greater than half of residual ash last year... Agreed that it may seem a little far fledged, but since its option A, i'll keep it as a contender.
C) Now if City services contain larger proportion of recycle materials this year than last year, then residual ash will be lesser than last year.. .But in hindsight, there is no guarantee that it will half of last year...
D) Makes sense.. its at this point i get confused between A and D.
Though in hindsight, Trucks coming out of nowhere in the argument could have been an indicator that answer choice should address Truckloads.
Phew! Tough World.
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mmslf75 wrote:Last year all refuse collected by Shelbyville city /services was incinerated. This incineration generated a large quantity of residual ash. In order to reduce the amount of residual ash Shelbyville generates this year to half of last year's total, the city has revamped its collection program. This year city services will separate for recycling enough refuse to reduce the number of truckloads of refuse to be incinerated to half of last year's number.
Which of the following is required for the revamped collection program to achieve its aim?
(A) This year, no materials that city services could separate for recycling will be incinerated.
(B) Separating recyclable materials from materials to be incinerated will cost Shelbyville less than half what it cost last year to dispose of the residual ash.
(C) Refuse collected by city services will contain a larger proportion of recyclable materials this year than it did last year.
(D) The refuse incinerated this year will generate no more residual ash per truckload incinerated than did the refuse incinerated last year.
(E) The total quantity of refuse collected by Shelbyville city service's this year will be no greater than that collected last year.
The main aim here is to 'reduce the amount of residual ash' no matter what the quantity of refuse is. Only (D) fulfills this requirement by stating that this year the residual ash per truckload will not be more than residual ash per truckload last year. Hence (D) is correct.
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How so?The approach you suggested to CR questions is opposite to what most instructors or even CR books tell us. When i first read the question i found 3 choices to be contenders.
The approach I teach is Kaplan's predict and match strategy. You get rewarded for reasoning to the correct answer, not for articulating multiple reasons why wrong answers are wrong. In quant, when you know the correct answer, do you then proceed to figure out why all the wrong answers are wrong? Of course not because that would be a waste of time. Same thing here: CR is just as objective as quant. And most correct answers can be predicted. Sometimes we can make very specific predictions; other times we predict the behavior of the correct answer.
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I find all the methods of contender.. blah..blah.. very time consuming.
reasoning and coming up with an analysis and picking the answer that has the analysis while eliminating
those out of scope is the best and quickest, IMO.
after all, everyone has diff approaches.
in this case they expect to reduce the amount of ashes by exactly half by halving amount of refuse .
this is only possible when the amount of ash per refuse remains the same.
reasoning and coming up with an analysis and picking the answer that has the analysis while eliminating
those out of scope is the best and quickest, IMO.
after all, everyone has diff approaches.
in this case they expect to reduce the amount of ashes by exactly half by halving amount of refuse .
this is only possible when the amount of ash per refuse remains the same.
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I also marked C while doing the question first time.
But, now I have understood why the answer is D and not C.
Thanks...
But, now I have understood why the answer is D and not C.
Thanks...
Sahil Chaudhary
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how would we eliminate option A?
i chose this as the answer as if they do not incinerate the materials that they have separated for recycling then there would not be ash from this which would mean that the refuse has decreased there by less number of truckloads of refuse to be incinerated and hence less residual ash.
i chose this as the answer as if they do not incinerate the materials that they have separated for recycling then there would not be ash from this which would mean that the refuse has decreased there by less number of truckloads of refuse to be incinerated and hence less residual ash.
Yes, can someone please explain why A is incorrect?
I had narrowed it down to A and D but chose A. Can someone explain why A is incorrect?
Answer choice A states - "This year, no materials that city services could separate for recycling will be incinerated".
Earlier in the stimuli, it stated that the "city will separate enough for recycling to reduce the number of truckloads". Doesn't that mean that the writers are assuming that the recyclable materials will NOT be incinerated, hence reducing the ash. If that's the case, option A is confirming that exact assumption so why is it wrong?
I had narrowed it down to A and D but chose A. Can someone explain why A is incorrect?
Answer choice A states - "This year, no materials that city services could separate for recycling will be incinerated".
Earlier in the stimuli, it stated that the "city will separate enough for recycling to reduce the number of truckloads". Doesn't that mean that the writers are assuming that the recyclable materials will NOT be incinerated, hence reducing the ash. If that's the case, option A is confirming that exact assumption so why is it wrong?
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Hi,fibbonnaci wrote:Hey let me explain the stimulus clearly,
City S sent 100 truck loads of refuse to be incinerated.
say the 100 truck loads of refuse led to 1000 kg of residual ash.
Now the city wants to reduce the amount of ash it produced last year (500 kg)
so how does it proceed to do this? by reducing the number of truck loads say 50.
wat is the inherent assumption in this plan?
The conversion of the truckload to residual ash remains the same.
for eg. in our case if 50 truck loads led to even greater proportion of residual ash say 1000 kg as opposed to 100 trucks leading to 1000 kg of ash, our conclusion falls apart. The program cannot be successful.
Our dear author makes this assumption that the conversion would be proportional.
This question is infact nicely worded assumption question. All u need to do here is find the assumption involved.
If u observe closely u will notice that this is a defender assumption, wherein the assumption protects the status quo of the passage.
following the above reasoning, in C, Even if a larger proportion of recyclable materials are segregated this year, if the proportional conversion of the refuse to ash not assumed, does this hold good?
That is the plain reason we eliminate C.
In option D "No more residual ash per truckload ...than...last year"
No more than means either equal or less.
If we consider as EQUAL how the ash is reduced to exactly HALF instead it will produce the same amount of ash as last year.
If we consider LESS ,how exactly it is half .Ash could also be more than half but less than last year.
How option D is right ?
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Hi kumarsaravana,
The last sentence of the prompt tells us "This year city services will separate for recycling enough refuse to REDUCE THE NUMBER OF TRUCKLOADS of refuse to be incinerated to HALF of last year's number." This means that the city will remove recyclable trash instead of incinerating it, which logically means that LESS trash will be burned. However, we have to consider the possibility that whatever trash IS incinerated COULD generate MORE ash (since different types of trash would likely create different amounts of ash). Answer D tells us that this possibility will NOT happen, so the plan should achieve its aim.
GMAT assassins aren't born, they're made,
Rich
The last sentence of the prompt tells us "This year city services will separate for recycling enough refuse to REDUCE THE NUMBER OF TRUCKLOADS of refuse to be incinerated to HALF of last year's number." This means that the city will remove recyclable trash instead of incinerating it, which logically means that LESS trash will be burned. However, we have to consider the possibility that whatever trash IS incinerated COULD generate MORE ash (since different types of trash would likely create different amounts of ash). Answer D tells us that this possibility will NOT happen, so the plan should achieve its aim.
GMAT assassins aren't born, they're made,
Rich
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PLAN: To reduce by half the NUMBER OF TRUCKLOADS of refuse to be incinerated.kumarsaravana wrote: Hi,
In option D "No more residual ash per truckload ...than...last year"
No more than means either equal or less.
If we consider as EQUAL how the ash is reduced to exactly HALF instead it will produce the same amount of ash as last year.
If we consider LESS ,how exactly it is half .Ash could also be more than half but less than last year.
How option D is right ?
CONCLUSION: The AMOUNT OF ASH that is incinerated will be reduced by half.
The correct answer is WHAT MUST BE TRUE for the conclusion to be valid.
Apply the NEGATION TEST.
When the correct answer choice is negated, the argument will fall apart.
D, negated:
The refuse incinerated this year will generate more residual ash per truckload.
If every truckload of refuse generates more ash, then the argument cannot conclude that the amount of ash will be reduced by half.
Consider an easy case:
Last year, 2 truckloads each generate 50 pounds of ash, for a total of 100 pounds of ash.
This year, 1 truckload generates 51 pounds of ash, with the result that the amount of ash is reduced by only 49% -- LESS THAN HALF.
Since the negation of D trashes the conclusion, D is WHAT MUST BE TRUE for the conclusion to be valid.
The correct answer is D.
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My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
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