IMO C...
This clearly tells the reason why collection got reduced...

OA plz

d is clearly incorrect, as underground mines have not been even mentioned ...
c is wrong because we just do wrong job

If we advantage from using number/rates, we could notice that cost of reclamation is charged per ton, i.e. physically per kg. By careful reading, we also notice that technology has not improved since the introduction of reclamation regulations - which means the cost is charged per ton and technically no change was made in the way the reclamation cost was allocated

the cost of reclamation is 4 bucks today, and it used to be approx. 9 bucks 20 years back

option b is attracting us by its may be true statement as per our general knowledge - and this why it must be trap (wrong)

much better with a and e now - 50/50

a is too specific and too narrow, not in any place in text we have encountered coal mine operations beyond the country (in other countries)

it must be e -- greater coal comes from the surface areas and the reclamation cost goes down

BellTheGMAT wrote:IMO C...
This clearly tells the reason why collection got reduced...

OA plz

OA is C

there's no point to mountainous areas in text
clueless how it's c

this is an incomplete assumption to ascertain that the average cost of reclamation went down because surface mining in mountainous areas has been ceased. Not in any place in text we are provided with the volume of surface mining comparatively described with the volume of non-mountainous surface mining - correspondingly mined-out land costs, i.e. reclamation costs of land in mountainous areas vs. non-mountainous areas

The point is we have fall in cost more than twice and the relative proportions of mountainous vs. non-mountainous surface mining aren't clear

i agree the average goes down, but that doesn't help

may be it's logical according to GMAT Prep, but it's quite not logical if we employ not even formal logic as LSAT requires but simple analysis

if it's c then we must make another assumption, which leaves us open to weaken/strengthen venues again

garima99 wrote:

BellTheGMAT wrote:IMO C...
This clearly tells the reason why collection got reduced...

OA plz

OA is C

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?

When a passage asks us to account for an APPARENT CONTRADICTION:

1. Identify the TWO FACTS that seem to contradict each other.
2. Look for an answer choice that explains HOW BOTH FACTS CAN BE TRUE at the same time.

In the passage above:

Fact 1: Reclamation TECHNOLOGY has not improved.
Fact 2: The AVERAGE COST of reclamation has decreased significantly.

Question: How can both facts can be true at the same time?
Answer: There must be a REASON that the AVERAGE COST of reclamation has decreased significantly.

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. Outside the scope. The argument is not about the cost of OPERATING the coal mines but about the cost of RECLAIMING the coal mines.

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. Outside the scope. The argument is not about the USE OF COAL but about the cost of RECLAIMING the mines. While the USE OF COAL might affect PROFITS, it does not affect the ratio of reclamation COSTS to production COSTS.

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. Bingo! This answer choice explains why the AVERAGE cost of reclamation has DECREASED: mine operators are no longer operating in areas where the cost of reclaiming a mine is HIGH, thus lowering the AVERAGE cost of reclamation.

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. Does not explain why the ratio of RECLAMATION COSTS to PRODUCTION COSTS has decreased.

E. As compared to twenty years ago, a greater percentage of the coal mined in Balzania today comes from surface mines. Outside the scope. Does not explain why the average cost of RECLAIMING a mine has decreased.

The correct answer is C.

revised for not understood thoroughly what the question was asking.

GMATGuruNY 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?

When a passage asks us to account for an APPARENT CONTRADICTION:

1. Identify the TWO FACTS that seem to contradict each other.
2. Look for an answer choice that explains HOW BOTH FACTS CAN BE TRUE at the same time.

In the passage above:

Fact 1: Reclamation TECHNOLOGY has not improved.
Fact 2: The AVERAGE COST of reclamation has decreased significantly.

Question: How can both facts can be true at the same time?
Answer: There must be a REASON that the AVERAGE COST of reclamation has decreased significantly.

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. Bingo! This answer choice explains why the AVERAGE cost of reclamation has DECREASED: mine operators are no longer operating in areas where the cost of reclaiming a mine is HIGH, thus lowering the AVERAGE cost of reclamation.

E. As compared to twenty years ago, a greater percentage of the coal mined in Balzania today comes from surface mines. Outside the scope. Does not explain why the average cost of RECLAIMING a mine has decreased.

The correct answer is C.

Mitch,

I am still confused with C and E.

In my view cost (per tonne) can come down in 2 ways:
1) when there is high production (volume or demand)
2) when there is little deamnd

C - 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.

talks about (2) when surface mining reduces, the need for reclaimation comes down as well. less demand leads to lower cost

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

In this case demand (need) for reclaimation is higher and therefore reclimation cost is spread across higher volume, leading to lower cost. This also appears as a viable option. But if I look deep, GREATER PERCENTAGE does not necessarily mean higher volume (overall volume could be lesser than that 20yrs ago) - in such a case, cost may not come out. Is this the reason to drop E.

Pls explain.

patanjali.purpose wrote:
Mitch,

I am still confused with C and E.

In my view cost (per tonne) can come down in 2 ways:
1) when there is high production (volume or demand)
2) when there is little deamnd

C - 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.

talks about (2) when surface mining reduces, the need for reclaimation comes down as well. less demand leads to lower cost

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

In this case demand (need) for reclaimation is higher and therefore reclimation cost is spread across higher volume, leading to lower cost. This also appears as a viable option. But if I look deep, GREATER PERCENTAGE does not necessarily mean higher volume (overall volume could be lesser than that 20yrs ago) - in such a case, cost may not come out. Is this the reason to drop E.

Pls explain.

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 answer choice explains why the average cost to reclaim a mine has decreased: the mines that are MORE EXPENSIVE to reclaim -- those in the mountainous areas -- are NO LONGER BEING USED.
Since only the cheaper-to-reclaim mines are being used, the average cost to reclaim a mine has decreased.

E: As compared to twenty years ago, a greater percentage of the coal mined in Balzania today comes from surface mines.
Be skeptical of PERCENTAGES.
We have no information about the total amount of coal or the total number of surface mines.
Even if a greater percentage of Balzania's coal is coming from surface mines, it's entirely possible that the amount of coal PER SURFACE MINE has DECREASED -- with the result that the cost to coal ratio for each mine would be expected to INCREASE.
Eliminate E.