GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

It is currently 22 Feb 2020, 21:14

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

Twenty years ago, Balzania put in place regulations requiring operator

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

Hide Tags

Find Similar Topics 
Director
Director
avatar
Joined: 26 Apr 2004
Posts: 787
Location: Taiwan
Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post Updated on: 05 Nov 2018, 03:37
13
112
00:00
A
B
C
D
E

Difficulty:

  75% (hard)

Question Stats:

60% (02:04) correct 40% (02:33) wrong based on 2122 sessions

HideShow timer Statistics

Twenty years ago, Balzania put in place regulations requiring operators of surface mines to pay for the reclamation of mined-out land. Since then, reclamation technology has not improved. Yet, the average reclamation cost for a surface coal mine being reclaimed today is only four dollars per ton of coal that the mine produced, less than half what it cost to reclaim surface mines in the years immediately after the regulations took effect.

Which of the following, if true, most helps to account for the drop in reclamation costs described?


A. Even after Balzania began requiring surface mine operators to pay reclamation costs, coal mines in Balzania continued to be less expensive to operate than coal mines in almost any other country.

B. In the twenty years since the regulations took effect, the use of coal as a fuel has declined from the level it was at in the previous twenty years.

C. Mine operators have generally ceased surface mining in the mountainous areas of Balzania because reclamation costs per ton of coal produced are particularly high for mines in such areas.

D. Even after Balzania began requiring surface mine operators to pay reclamation costs, surface mines continued to produce coal at a lower total cost than underground mines.

E. As compared to twenty years ago, a greater percentage of the coal mined in Balzania today comes from surface mines.


Verbal Question of The Day: Day 104: Critical Reasoning


Subscribe to GMAT Question of the Day: E-mail | RSS
For All QOTD Questions Click Here

Source : GMATPrep Default Exam Pack

Originally posted by chunjuwu on 24 Dec 2004, 21:49.
Last edited by Bunuel on 05 Nov 2018, 03:37, edited 1 time in total.
Renamed the topic and edited the question.
Most Helpful Expert Reply
Veritas Prep GMAT Instructor
User avatar
V
Joined: 16 Oct 2010
Posts: 10113
Location: Pune, India
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 24 Feb 2014, 22:07
24
16
Zatmah wrote:
Twenty years ago, Balzania put in place regulations requiring operators of surface mines to pay for the reclamation of mined-out land. Since then, reclamation technology has not improved. Yet, the average reclamation cost for a surface coal mine being reclaimed today is only four dollars per ton of coal that the mine produced, less than half what it cost to reclaim surface mines in the years immediately after the regulations took effect.

Which of the following, if true, most helps to account for the drop in reclamation costs described?

A. Even after Balzania began requiring surface mine operators to pay reclamation costs, coal mines in Balzania continued to be less expensive to operate than coal mines in almost any other country.
B. In the twenty years since the regulations took effect, the use of coal as a fuel has declined from the level it was at in the previous twenty years.
C. Mine operators have generally ceased surface mining in the mountainous areas of Balzania because reclamation costs per ton of coal produced are particularly high for mines in such areas.
D. Even after Balzania began requiring surface mine operators to pay reclamation costs, surface mines continued to produce coal at a lower total cost than underground mines.
E. As compared to twenty years ago, a greater percentage of the coal mined in Balzania today comes from surface mines.


The question is very simple if you understand exactly what reclamation costs are. Once some land is mined out, it needs work to be put back to some use say cultivation. That work is expensive and operators need to pay the govt for reclamation. When will the average reclamation cost go down? When technology gets better and it costs less to reclaim everywhere. Or when areas with high reclamation costs are not mined.

Option (C) tells you that mining in a particularly high reclamation cost area has stopped. This will decrease average reclamation cost (though the reclamation cost of other areas might still be the same)

None of the other options are relevant. In option (B), even if use of coal has declined and less coal is being mined today, it doesn't change the reclamation cost. Once a place is mined out, it will take the same amount of money to reclaim it.

Answer (C)
_________________
Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >
GMAT Club Verbal Expert
User avatar
D
Status: GMAT and GRE tutors
Joined: 13 Aug 2009
Posts: 3162
Location: United States (CO)
GMAT 1: 780 Q51 V46
GMAT 2: 800 Q51 V51
GRE 1: Q170 V170

GRE 2: Q170 V170
Re: QOTD: Twenty years ago, Balzania put in place  [#permalink]

Show Tags

New post 14 Sep 2017, 11:12
20
5
We are told that operators of surface mines have had to pay for the reclamation of mined-out land for the past twenty years. During that time, reclamation technology has not improved. Yet, the average reclamation cost for a surface coal mine being reclaimed today is significantly less than what it was twenty years ago.

So why has the average reclamation cost decreased even though the technology has not improved?

Quote:
A. Even after Balzania began requiring surface mine operators to pay reclamation costs, coal mines in Balzania continued to be less expensive to operate than coal mines in almost any other country.

We are not concerned with how the reclamation costs in Balzania compare to those in other countries. We are trying to explain why the average reclamation cost IN BALZANIA has decreased even though the technology has not improved. Eliminate (A).

Quote:
B. In the twenty years since the regulations took effect, the use of coal as a fuel has declined from the level it was at in the previous twenty years.

A decline in the use of coal might have caused a decrease in surface coal mining and thus an OVERALL decrease in reclamation costs, but that would not affect AVERAGE reclamation cost. Eliminate (B).

Quote:
C. Mine operators have generally ceased surface mining in the mountainous areas of Balzania because reclamation costs per ton of coal produced are particularly high for mines in such areas.

Before the regulations, operators did not have to pay for the reclamation of mined-out land, so they would have had no incentive to consider those costs when choosing mining sites. However, since the passing of the regulations, the operators HAVE had incentive to consider reclamation costs when choosing mining sites. As a result, the operators might have started to avoid mining in areas that would incur high reclamation costs (i.e. mountainous areas), thus reducing average reclamation cost. Choice (C) would help to explain why average reclamation cost has decreased even though the technology has not improved, so keep (C).

Quote:
D. Even after Balzania began requiring surface mine operators to pay reclamation costs, surface mines continued to produce coal at a lower total cost than underground mines.

We need a statement that explains why the average reclamation cost for a SURFACE coal mine has decreased. How those costs compare to those of underground mines is irrelevant, so (D) can be eliminated.

Quote:
E. As compared to twenty years ago, a greater percentage of the coal mined in Balzania today comes from surface mines.

Increasing the amount of coal from surface mines might increase the TOTAL reclamation costs from those sites, but, as with choice (B), this would not explain why the AVERAGE reclamation cost has changed. Choice (E) might explain why the operators of such mines are making more money, but it does not explain the change in reclamation costs. Eliminate (E).

Choice (C) is the best answer.
_________________
GMAT/GRE tutors @ www.gmatninja.com (we're hiring!) | GMAT Club Verbal Expert | Instagram | Blog | Bad at PMs

Beginners' guides to GMAT verbal: RC | CR | SC

YouTube LIVE verbal webinars: all videos by topic

SC articles & resources: How to go from great (760) to incredible (780) on GMAT SC | That "-ing" Word Probably Isn't a Verb | That "-ed" Word Might Not Be a Verb, Either | No-BS Guide to GMAT Idioms | "Being" is not the enemy | WTF is "that" doing in my sentence?

RC, CR, and other articles & resources: All GMAT Ninja articles on GMAT Club | Using LSAT for GMAT CR & RC |7 reasons why your actual GMAT scores don't match your practice test scores | How to get 4 additional "fake" GMAT Prep tests for $29.99 | Time management on verbal

SC & CR Questions of the Day (QOTDs), featuring expert explanations: All QOTDs | Subscribe via email | RSS

Need an expert reply? Hit the request verbal experts' reply button; be specific about your question, and tag @GMATNinja. Priority is always given to official GMAT questions.
Most Helpful Community Reply
VP
VP
User avatar
Joined: 03 Jan 2005
Posts: 1492
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 11 Jun 2005, 20:06
12
7
Fact: 20 years ago a regulation started.
Fact: tech not improved since then.
Fact: cost is halved.

Ask for explanation.


A. Even after Balzania began requiring surface mine operators to pay reclamation costs, coal mines in Balzania continued to be less expensive to operate than coal mines in almost any other country.
Talk about cost of coal mines, not reclamatin of coal mines, irrelevant.

B. In the twenty years since the regulations took effect, the use of coal as a fuel has declined from the level it was at in the previous twenty years.
Talks about use of coal. Irrelevant.

C. Mine operators have generally ceased surface mining in the mountainous areas of Balzania because reclamation costs per ton of coal produced are particularly high for mines in such areas.
This explains the drop in average cost. The reason is high cost area do not get to be used any more.

D. Even after Balzania began requiring surface mine operators to pay reclamation costs, surface mines continued to produce coal at a lower total cost than underground mines.
Talks about coal costs. Irrelevant.

E. As compared to twenty years ago, a greater percentage of the coal mined in Balzania today comes from surface mines.
Do not explain why the reclaimation cost would decrease when more surface mines are used.

C
General Discussion
Intern
Intern
avatar
Joined: 17 Dec 2004
Posts: 14
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 25 Dec 2004, 10:08
2
I think C is better coz....

A - Not comparing cost in Balzania and other countries;
B - it is related to demand but not cost;
D - Not comparing surface and underground mine;

C and E left

For E, larger % from surface mine, as we donno the change in absolute total cost and total quantity, may or may not reduce the cost per ton

But for C, if we remove the higher cost per ton from the portfolio, the average cost per tone will drop

So C is the answer.
Director
Director
avatar
Joined: 26 Apr 2004
Posts: 787
Location: Taiwan
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 27 Dec 2004, 09:42
4
Hello, the OA should be C, here is my reasoning.

In this question, we can assume there are two kinds of mining methods, one is surface mining which needs to pay and the other is underground mining which needs not to pay.
Then we compare the two mining periods. We can assume...

1:THe years immediately after the regulation took effect

The total cost is $400, and the total tons of coal including surface and underground are 2 tons. So, we get the average cost $200 per ton.

2: Today
The total cost is still 400, because surface mining is ceased. However, the total tons of coal are still increasing. We can assume 4 tons of coal . Then, the average cost will be $100 per ton.

Therefore, the OA is C.

How do you think? Am I right?

Thank you
Intern
Intern
User avatar
Joined: 18 Nov 2004
Posts: 49
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 11 Jun 2005, 17:47
2
1
I don't see the reasons behind why "B" is correct. Could you please explain.

I'll go with C on this one.

Why I think B is wrong:
We are talking about X = [$cost/1ton], Lets assume that they were mining 20 mines before (hence need to fix 20 of them). Because the consumption came down, say they need to mine only 10 now (hence they need to fix only 10). - So, X remains the same, isn't it?
The above assumes, that all mines produce the same amt of coal on an average. Hence, I don't see why X goes down.

Why I think E is wrong:
This one talks about "percentage" and should be very careful. You could get more percentage by not changing anything with surface-mining from 20 yrs ago and just taking down the production from underground mines. Hence, this does not give any information about surface mines.

I'm curious to know what the OA is.
-FM
Manager
Manager
avatar
Joined: 04 May 2005
Posts: 52
Location: Austin, Texas
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 12 Jun 2005, 15:37
1
1
ttar wrote:
Twenty years ago, Balzania put in place regulations requiring operators of surface mines to pay for the reclamation of mined-out land. Since then, reclamation technology has not improved. Yet, the average reclamation cost for a surface coal mine being reclaimed today is only four dollars per ton of coal that the mine produced, less than half what it cost to reclaim surface mines in the years immediately after the regulations took effect. Which of the following, if true, most helps to account for the drop in reclamation costs
described?

C. Mine operators have generally ceased surface mining in the mountainous areas of Balzania because reclamation costs per ton of coal produced are particularly high for mines in such areas.


(C).
Often, more productive technology makes things cheaper over time. But that is NOT the case here. If not better technology, it must be something about how mines are operated when in use, that makes their later reclamation cheaper. (C) addresses this: mine operators are now working locations that are cheaper to reclaim.

(The only alternate explanation would be, say, general deflation making everything cheaper. But that's not an answer choice).
Director
Director
User avatar
Joined: 01 Apr 2008
Posts: 587
Name: Ronak Amin
Schools: IIM Lucknow (IPMX) - Class of 2014
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 13 Jul 2009, 10:41
I have a feeling it should be E. OA pls?

Why not C> We are talking about average reclamation cost. Now if the mining is 'ceased' in mountainous areas then this area wont be considered in calculating the average cost of reclamation.

Why E> If greater percentage of coal is mined now from surface mines then the average cost will come down.

ritjn2003 wrote:
Twenty years ago, Balzania put in place regulations requiring operators of surface mines
to pay for the reclamation of mined-out land. Since then, reclamation technology has not
improved. Yet, the average reclamation cost for a surface coal mine being reclaimed
today is only four dollars per ton of coal that the mine produced, less than half what it
cost to reclaim surface mines in the years immediately after the regulations took effect.
Which of the following, if true, most helps to account for the drop in reclamation costs
described?
A. Even after Balzania began requiring surface mine operators to pay reclamation
costs, coal mines in Balzania continued to be less expensive to operate than coal
mines in almost any other country.
B. In the twenty years since the regulations took effect, the use of coal as a fuel has
declined from the level it was at in the previous twenty years.
C. Mine operators have generally ceased surface mining in the mountainous areas of
Balzania because reclamation costs per ton of coal produced are particularly high
for mines in such areas.
D. Even after Balzania began requiring surface mine operators to pay reclamation
costs, surface mines continued to produce coal at a lower total cost than
underground mines.
E. As compared to twenty years ago, a greater percentage of the coal mined in
Balzania today comes from surface mines.
Senior Manager
Senior Manager
avatar
Joined: 05 Jun 2009
Posts: 329
WE 1: 7years (Financial Services - Consultant, BA)
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 20 Jul 2009, 09:07
2
Economist wrote:
I have a feeling it should be E. OA pls?
Why not C> We are talking about average reclamation cost. Now if the mining is 'ceased' in mountainous areas then this area wont be considered in calculating the average cost of reclamation.


Average = (X + Y+ Z....) /N

But if you remove higher values of the set, the average goes down. That's the intent of the option C

Economist wrote:
Why E> If greater percentage of coal is mined now from surface mines then the average cost will come down.

Why? This doesn't affect the average reclamation cost ($/ton).

Increase in surface mines => Increase in Coal Amount ==> But reclamation cost remains the same ($/ton) as technology doesn't change.

Here, C is correct. Example of above,

there are no. of shops sell item at price x,y,z / item. x>y>z

and tax = t%
from shop 1 => tx will be tax
shop2 => ty
shop 3 ==> tz

As shop1 is selling item at higher price, it is giving more tax /item than other shop.

So if shop1 is removed and only shop2 and shop3 types remain in the market average tax/item will decline.

Reclamation cost is similar to tax in this case; mountainous area is similar to the shop1.
Manager
Manager
avatar
Status: Time to apply!
Joined: 24 Aug 2011
Posts: 112
Location: India
Concentration: Finance, Entrepreneurship
GMAT 1: 600 Q48 V25
GMAT 2: 660 Q50 V29
GMAT 3: 690 Q49 V34
GPA: 3.2
WE: Engineering (Computer Software)
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 25 Oct 2011, 23:16
1
Problem with B :
It says that the use of coal has been reduced. But that doesn't mean that mining is ceased. It its quite possible that the mining is still continued and the coal is exported to other countries.

Explanation of C ( CORRECT answer)

Let there be 3 sites in Balzania - site 1 , 2 and 3 - where surface mines were operated .
Let a , b and c tons of coal were processed from the 3 sites respectively
and the cost for reclamation be c1, c2 and c3 respectively.

then the average reclamation cost : (ac1 + bc2 + cc3)/ (a+ b+ c)
Now let site 3 be the mountainous area.

Now if site 3 stops mining,
then the average reclamation cost : (ac1 + bc2)/ (a+ b)

It is given that c3 is very high. Hence the new average reclamation cost should decrease provided the value of c is very small.

But this is the best answer here and we should go with choice C.
Director
Director
avatar
Joined: 03 Aug 2012
Posts: 651
Concentration: General Management, General Management
GMAT 1: 630 Q47 V29
GMAT 2: 680 Q50 V32
GPA: 3.7
WE: Information Technology (Investment Banking)
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 19 Feb 2013, 21:17
Twenty years ago, Balzania put in place regulations requiring operators of surface mines
to pay for the reclamation of mined-out land. Since then, reclamation technology has not
improved. Yet, the average reclamation cost for a surface coal mine being reclaimed
today is only four dollars per ton of coal that the mine produced, less than half what it
cost to reclaim surface mines in the years immediately after the regulations took effect.

P1: -20 yrs -- regulations -- operators pay reclamation amount

P2: reclamation technology has not improved

C: Today : Cost is 4 $/ton as compared to >=10 $/ton before 20 yrs after regulations took place.


IMO The answer should be (E). As stated below:


Just after regulations : Total Coal : 1000 , Coal from surface mines: 100 (10%)

Now : Total Coal: 1000 ,Coal from surface mines: 200 (20%)

Other things being equal , if you are increasing the denominator than the expression will decrease.Here tons have increased ,thereby decreasing the dollar per ton Value.


Plz Advice !!
e-GMAT Representative
User avatar
P
Joined: 02 Nov 2011
Posts: 2976
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 19 Feb 2013, 21:31
1
@targetgmatchotu - I dont believe you are reading the question correctly. The reclamation costs refer only to the coal produced from surface mines, not the total coal produced. Hence, the reclamation costs/ton of coal do not change regardless of whether surface mine satisfy half or country's demand or 20% of the demand.

-Rajat
_________________
Manager
Manager
avatar
Joined: 22 Nov 2010
Posts: 216
Location: India
GMAT 1: 670 Q49 V33
WE: Consulting (Telecommunications)
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 20 Feb 2013, 02:53
Twenty years ago, Balzania put in place regulations requiring operators of surface mines
to pay for the reclamation of mined-out land. Since then, reclamation technology has not
improved. Yet, the average reclamation cost for a surface coal mine being reclaimed
today is only four dollars per ton of coal that the mine produced, less than half what it
cost to reclaim surface mines in the years immediately after the regulations took effect.
Which of the following, if true, most helps to account for the drop in reclamation costs
described?
A. Even after Balzania began requiring surface mine operators to pay reclamation
costs, coal mines in Balzania continued to be less expensive to operate than coal
mines in almost any other country. . Out of scope. No comparison with other country is mentioned above
B. In the twenty years since the regulations took effect, the use of coal as a fuel has
declined from the level it was at in the previous twenty years. Passage is about average reclamation cost for a surface coal mine, not about use of coal
C. Mine operators have generally ceased surface mining in the mountainous areas of
Balzania because reclamation costs per ton of coal produced are particularly high
for mines in such areas.
D. Even after Balzania began requiring surface mine operators to pay reclamation
costs, surface mines continued to produce coal at a lower total cost than
underground mines. OFS: Passage do not mention about any comparision
E. As compared to twenty years ago, a greater percentage of the coal mined in
Balzania today comes from surface mines. Passage is about average reclamation cost for a surface coal mine
_________________
YOU CAN, IF YOU THINK YOU CAN
Retired Moderator
User avatar
Joined: 15 Jun 2012
Posts: 976
Location: United States
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 06 Apr 2013, 14:09
3
1
Nice question. I picked D and got it wrong. But after review, C is the best.
This is resolve the paradox, so we don't have conclusion here, just fact.
Fac1: 20 years ago, there was a regulations requiring operators to pay for the reclamation.
Fac 2: Reclamation technology has not improve
Fac 3: But the AVERAGE reclamation cost today is 1/2 compared to that of 20 years ago.

Why: Key word here is AVERAGE reclamation cost (ARC). ARC is calculated from reclamation cost in Balzania, and reclamation costs from other areas. ARC will reduce, if operators move from high cost areas to lower cost areas. It means operators moved out Balzania to areas that have lower reclamation cost. That is C.


anish123ster wrote:
n y not B..???


B is out because it talks about the reduction of quantity (Q), but average cost couldn't decrease if cost/ton - Price (P) - did not decrease.
To be more clear, let try the equation.

Average cost = [Q1xP1 + Q2xP2 + ...........+ QnxPn] / [Q1 + Q2 +.....+ Qn]
Q1 = quantity in area 1; P1 = reclamation cost/ton in area 1
Q2 = quantity in area 2; P2 = reclamation cost/ton in area 2

B says [Q1 + Q2 +.....+ Qn] reduced, it means only the denominator decreased, but it doesn't say the numerator also decreased.
What if Q decreased, but P increased! Average cost will not decrease.

I hope it helps.

___________________________
Please kudo if my post helps!
Senior Manager
Senior Manager
avatar
B
Joined: 03 May 2013
Posts: 262
Location: India
Concentration: Operations, Human Resources
Schools: XLRI GM"18
GPA: 4
WE: Human Resources (Human Resources)
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 26 Jan 2014, 11:32
CONCLUSION- Average reclamation cost for a surface coal mine being reclaimed today is less than half what it cost to reclaim surface mines in the years immediately after the regulations took effect.

Which of the following, if true, most helps to account for the drop in reclamation costs described?

A. Even after Balzania began requiring surface mine operators to pay reclamation costs, coal mines in Balzania continued to be less expensive to operate than coal mines in almost any other country.NO. WE TALK OF RECLAMATION COST HERE NOT COAL COST
B. In the twenty years since the regulations took effect, the use of coal as a fuel has declined from the level it was at in the previous twenty years.COAL QUANTITY BEING USED IRRELEVANT.....
C. Mine operators have generally ceased surface mining in the mountainous areas of Balzania because reclamation costs per ton of coal produced are particularly high for mines in such areas. THE MINE OPERATORS ARE CLEVER.... THEY HAVE REDUCED THE AVERAGE RECLAMATION COST BY REDUCING UPON HIGHER RECLAMATION RATE AREAS....
D. Even after Balzania began requiring surface mine operators to pay reclamation costs, surface mines continued to produce coal at a lower total cost than underground mines.NO SUCH COMPARISON REQUIRED HERE
E. As compared to twenty years ago, a greater percentage of the coal mined in Balzania today comes from surface mines.WHERE COAL COMES FROM IS IRRELEVANT


KUDOS IF YOU PLEASE......
Magoosh GMAT Instructor
User avatar
G
Joined: 28 Dec 2011
Posts: 4476
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 24 Feb 2014, 15:46
3
2
Zatmah wrote:
Twenty years ago, Balzania put in place regulations requiring operators of surface mines to pay for the reclamation of mined-out land. Since then, reclamation technology has not improved. Yet, the average reclamation cost for a surface coal mine being reclaimed today is only four dollars per ton of coal that the mine produced, less than half what it cost to reclaim surface mines in the years immediately after the regulations took effect.

Which of the following, if true, most helps to account for the drop in reclamation costs described?

A. Even after Balzania began requiring surface mine operators to pay reclamation costs, coal mines in Balzania continued to be less expensive to operate than coal mines in almost any other country.
B. In the twenty years since the regulations took effect, the use of coal as a fuel has declined from the level it was at in the previous twenty years.
C. Mine operators have generally ceased surface mining in the mountainous areas of Balzania because reclamation costs per ton of coal produced are particularly high for mines in such areas.
D. Even after Balzania began requiring surface mine operators to pay reclamation costs, surface mines continued to produce coal at a lower total cost than underground mines.
E. As compared to twenty years ago, a greater percentage of the coal mined in Balzania today comes from surface mines.

Dear Zatmah,
I'm happy to help with this. :-)

Something changed --- not the technology itself, but something else --- and this change resulted in a drop in the cost of reclamation projects. We need some kind of change over the past twenty years that could account for this change.

A. Even after Balzania began requiring surface mine operators to pay reclamation costs, coal mines in Balzania continued to be less expensive to operate than coal mines in almost any other country.
This is about something that continues, so it cannot explain a change over the past twenty years. This is incorrect.

B. In the twenty years since the regulations took effect, the use of coal as a fuel has declined from the level it was at in the previous twenty years.
Well, the total amount of coal is not relevant, because the cost is "per ton of coal." It's a ratio (cost of reclamation)/(ton of coal), so even if the total amount of coal goes down, it's not at all clear that the cost of individual reclamation project would change. This is incorrect.

C. Mine operators have generally ceased surface mining in the mountainous areas of Balzania because reclamation costs per ton of coal produced are particularly high for mines in such areas.
Twenty years ago, mining in the mountain forests, lots of expensive reclamation projects. Now, fewer of those mining projects, so more projects with, on average, lower reclamation costs. That would lower the average cost in 20 years. This is a promising answer choice.

D. Even after Balzania began requiring surface mine operators to pay reclamation costs, surface mines continued to produce coal at a lower total cost than underground mines.
This is about the cost of doing the mining, which doesn't necessarily have any connection to the cost of the reclamation. This is incorrect.

E. As compared to twenty years ago, a greater percentage of the coal mined in Balzania today comes from surface mines.
First of all, more are from surface mines ... as opposed to ....??? underground mines?? Let's assume that is the implicit comparison. How does the cost of reclaiming surface mines compare to the cost of reclaiming underground mines? I have no earthy clue. We are not supposed to be experts at mining here, so we have no idea how these costs would compare and whether this factoid is relevant to the argument at all. This is not correct.

The only viable answer is (C).

You may find this blog relevant:
http://magoosh.com/gmat/2012/gmat-cr-paradox-questions/

Does all this make sense?
Mike :-)
_________________
Mike McGarry
Magoosh Test Prep


Education is not the filling of a pail, but the lighting of a fire. — William Butler Yeats (1865 – 1939)
Intern
Intern
avatar
Joined: 10 Mar 2013
Posts: 7
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 21 Mar 2015, 21:33
Mystery: Average reclamation cost for a surface coal mine being reclaimed today dropped (less than half what it usually cost) despite supposed increase in costs requiring operators of surface ines to pay for reclamation of mined-out land

Find answer with the best theory

A. Even after Balzania began requiring surface mine operators to pay reclamation costs, coal mines in Balzania continued to be less expensive to operate than coal mines in almost any other country.
    - We are not concerned with other countries. This is out of scope.
B. In the twenty years since the regulations took effect, the use of coal as a fuel has declined from the level it was at in the previous twenty years.
    - Although this may account for less use of coals as fuel, thereby affecting demand for coals in general and leading to a decrease in reclamation costs (law of supply & demand), we are only concerned about how Balzania’s increase in operational costs led to a decrease in surface mines’ operational costs in general. This does not address anything about Balzania. Does little in resolving the paradox.
C. Mine operators have generally ceased surface mining in the mountainous areas of Balzania because reclamation costs per ton of coal produced are particularly high for mines in such areas.
    - This is correct. This suggests that the costs are only high in Balzania, due to the regulation. The second statement in the prompt which suggests that average reclamation costs have dropped, applies to surface mines in general, not necessarily Balzania’s. So this makes sense, since it addresses the paradox -- despite Balzania’s increase in costs, other surface mining sites do not necessarily have to follow.
D. Even after Balzania began requiring surface mine operators to pay reclamation costs, surface mines continued to produce coal at a lower total cost than underground mines.
    - Nobody cares about how surface mines weigh against underground mines. It might affect the demand for coal mines, but this is not the main issue at hand.
E. As compared to twenty years ago, a greater percentage of the coal mined in Balzania today comes from surface mines.
    - This is only additional information that we do not necessarily need. It does not help in resolving the paradox.

B & C are neck and neck in this argument as they both explain the discrepancy. However, we will need to recognize the factors involved in the paradox and how they play in the theory being presented in the answer choices. B excludes Balzania’s increased operational costs, and C subtly includes it.
Manager
Manager
avatar
Joined: 06 Jul 2011
Posts: 77
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 16 May 2015, 13:09
I ended up choosing B. Here is my reasoning -

(B) In the twenty years since the regulations took effect, the use of coal as a fuel has declined from the level it was at in the previous twenty years.

Less coal is used as a fuel (leads to)--> Less mining is happening --> Less land is getting dug up --> Less reclamation cost.

(C) Mine operators have generally ceased surface mining in the mountainous areas of Balzania because reclamation costs per ton of coal produced are particularly high for mines in such areas.

I see this option as very narrow in scope. Let me explain -

Mining - Surface+underground
areas - Mountain+plains(regular)

This option talks about a very specific mining that has stopped i.e. surface mining in the mountainous areas. Now it is no where given how much this type of mining contributes to coal industry or what the effect on total reclamation cost would be,if we stop doing this.
Veritas Prep GMAT Instructor
User avatar
V
Joined: 16 Oct 2010
Posts: 10113
Location: Pune, India
Re: Twenty years ago, Balzania put in place regulations requiring operator  [#permalink]

Show Tags

New post 17 May 2015, 20:17
2
arkle wrote:
I ended up choosing B. Here is my reasoning -

(B) In the twenty years since the regulations took effect, the use of coal as a fuel has declined from the level it was at in the previous twenty years.

Less coal is used as a fuel (leads to)--> Less mining is happening --> Less land is getting dug up --> Less reclamation cost.



This is correct but not complete. Less land getting dug up implies less reclamation cost the the miner has to pay to the govt per year. So basically he is mining slowly. But we are talking about average reclamation cost in terms of dollar per ton of coal. You will pay the same dollar per ton of coal. This will not change if you mine the coal slower. You will just be paying the same amount after longer intervals.

arkle wrote:
(C) Mine operators have generally ceased surface mining in the mountainous areas of Balzania because reclamation costs per ton of coal produced are particularly high for mines in such areas.

I see this option as very narrow in scope. Let me explain -

Mining - Surface+underground
areas - Mountain+plains(regular)

This option talks about a very specific mining that has stopped i.e. surface mining in the mountainous areas. Now it is no where given how much this type of mining contributes to coal industry or what the effect on total reclamation cost would be,if we stop doing this.


Average of 4 numbers: 1, 2, 5, 100 is 27.
What if I remove the largest number 100? The average goes down to less than 3.
This is the same concept. The average cost goes down when an area where reclamation costs were very high stopped getting mined.

Note that average reclamation cost is a theoretical cost. It is is not what is charged. Every area is charged a different reclamation cost. Average just helps us get a feel for the combined effect of different reclamation costs.
_________________
Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >
GMAT Club Bot
Re: Twenty years ago, Balzania put in place regulations requiring operator   [#permalink] 17 May 2015, 20:17

Go to page    1   2    Next  [ 35 posts ] 

Display posts from previous: Sort by

Twenty years ago, Balzania put in place regulations requiring operator

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





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