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# Each December 31 in Country Q, a tally is made of the

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Each December 31 in Country Q, a tally is made of the [#permalink]

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22 Jan 2011, 03:18
5
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95% (hard)

Question Stats:

43% (01:48) correct 57% (02:14) wrong based on 487 sessions

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Each December 31 in Country Q, a tally is made of the country’s total available coal supplies—that is, the total amount of coal that has been mined throughout the country but not consumed. In 1991 that amount was considerably lower than it had been in 1990. Furthermore, Country Q has not imported or exported coal since 1970.

If the statements above are true, which one of the following must also be true on the basis of them?

(A) In Country Q, more coal was mined in 1990 than was mined in 1991.
(B) In Country Q, the amount of coal consumed in 1991 was greater than the amount of coal mined in 1991.
(C) In Country Q, the amount of coal consumed in 1990 was greater than the amount of coal consumed in 1991.
(D) In Country Q, the amount of coal consumed in 1991 was greater than the amount of coal consumed in 1990.
(E) In Country Q, more coal was consumed during the first half of 1991 than was consumed during the first half of 1990.
[Reveal] Spoiler: OA

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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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22 Jan 2011, 09:07
This seems odd. I would pick B.

As it states:
In 1991
that amount was considerably lower than it had been
in 1990.

That means that spare supplies of coal were lower in 1991 than in 1990, therefore by constant mining, in 1991 they consumed more coal: either mined in that year or from reserves from 1990.
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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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24 Jan 2011, 23:58
oh boy this was hard, i went over time and picked choice (A)

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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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25 Jan 2011, 00:23
IMO D ,
i eliminated E as irrelavant, B because it is comparing consumed to mined(not compared in the Q) and A as it is not necessarily true. between C and D i think D is correct as in order to get the number for 1991 less than that for 1990 the amount consumed must be significantly more to erase the left out balance of 1990 + coal freshly mined in 1991. C is stating the opposite
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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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25 Jan 2011, 01:01
Sorry Posted the Wrong OA by mistake.Guess the mouse slipped.OA B
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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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25 Jan 2011, 02:31
i got it now! B is indeed correct. if in 1990 10 kilos are produced out of which 8 kilos are consumed , then the number for 1990 would be 2 kilos. the number for 1991 to have less than that of 1990(less than 2 kilos), it should have a consumption large enough to nullify the amount mined in 1991 and then some more (this is because the figure for 1991 would be calculated by coal mined in 1991 - coal consumed in 1991 + amount left in 1990).
i shud hav read the choices carefully
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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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25 Jan 2011, 02:43
vinzycoolfire wrote:
i got it now! B is indeed correct. if in 1990 10 kilos are produced out of which 8 kilos are consumed , then the number for 1990 would be 2 kilos. the number for 1991 to have less than that of 1990(less than 2 kilos), it should have a consumption large enough to nullify the amount mined in 1991 and then some more (this is because the figure for 1991 would be calculated by coal mined in 1991 - coal consumed in 1991 + amount left in 1990).
i shud hav read the choices carefully
But the author is assuming the deficit . .I was checking whether U ppl found it fishy Or not
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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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25 Jan 2011, 03:00
the deficit is the only way that coal reserve of 1991 is going to be lesser than that of 1990. think about it!! How else can the figure reduce for 1991?? needless to say a deficit is not an "assumption" here.
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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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25 Jan 2011, 03:12
vinzycoolfire wrote:
the deficit is the only way that coal reserve of 1991 is going to be lesser than that of 1990. think about it!! How else can the figure reduce for 1991?? needless to say a deficit is not an "assumption" here.

You are not answering to my question
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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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25 Jan 2011, 03:30
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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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25 Jan 2011, 03:37
1
KUDOS
If the statements above are true, which one of the
following must also be true on the basis of them?
Pls Pay attention to Must
Its not a could be true question
What if the consumption was less than the mined quantity (and the amount left over after the consumption is less than the amount left over the previous year )and not more than the mined quantity
B is answer to a Could Be True Question.ie:It doesnt have to necessarily be True
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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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25 Jan 2011, 03:51
mundasingh123 can you answer this question
let's say the amount of coal mined in 1990 is 5 kilos.
and amount consumed in 1990 is 3 kilos.
the coal reserve figure for 1990 is 5 - 3 kilos = 2 kilos. still with me??
now let's say the amount mined in 1991 is 4 kilos.
and amount consumed is 3 kilos(NOTE:lesser than amount mined).
what will the coal reserve be?
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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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25 Jan 2011, 08:04
vinzycoolfire wrote:
mundasingh123 can you answer this question
let's say the amount of coal mined in 1990 is 5 kilos.
and amount consumed in 1990 is 3 kilos.
the coal reserve figure for 1990 is 5 - 3 kilos = 2 kilos. still with me??
now let's say the amount mined in 1991 is 4 kilos.
and amount consumed is 3 kilos(NOTE:lesser than amount mined).
what will the coal reserve be?

1
Bro,Thats the same thing i am telling U
According to B, Amt consumed > 4 Kgs ie gretaer than
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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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25 Jan 2011, 10:46
3
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no dude it is 3 kilos. 2 kilos of 1990 and 1 kilo in 1991. it is cumulative. why? because the 2 kilos(of 1990) will also be available for consumption, u can't take that out of the equation as the question does not define total coal available as amount mined PER year - amount consumed PER year. it just states "the total amount of coal that has been mined throughout the country but not consumed". so total available coal in 1991 should include amount left out in 1990 + amount left out in 1991.

now this is less than the 1990 figure, so obviously the left out amount in 1991 should be negative or in other words consumption is more than amount mined.

hope this helps.
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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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27 Jan 2011, 12:27
Good One mundasingh. Kudos to you for posting it.

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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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02 Feb 2011, 10:45
good one vinzycoolfire. +1 to you.

I was not thinking in cumulative terms.

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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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02 Feb 2011, 11:12
I understood the points raised by both parties here but just curious to know that if consumption was greater in 1991 than that of coal mined (1991), then answer choice D automaticaly becomes true. Isn't it??

Please shed some light on this issue.

Thanks
-V

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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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02 Feb 2011, 23:21
vineet474 wrote:
I understood the points raised by both parties here but just curious to know that if consumption was greater in 1991 than that of coal mined (1991), then answer choice D automaticaly becomes true. Isn't it??

Please shed some light on this issue.

Thanks
-V

thanx vineet474 for the kudos.
the point you are raising about D is not correct. if the consumption of 1991 is more than coal mined in 1991 it is sufficient to explain the scenario. no need for consumption of 1991 to be more than consumption of 1990(it maybe true but not necessary that it MUST be true). if still in doubt try it with an example and let me know your doubts. will try to help.
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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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03 Feb 2011, 07:09
3
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vinzycoolfire wrote:
vineet474 wrote:
I understood the points raised by both parties here but just curious to know that if consumption was greater in 1991 than that of coal mined (1991), then answer choice D automaticaly becomes true. Isn't it??

Please shed some light on this issue.

Thanks
-V

thanx vineet474 for the kudos.
the point you are raising about D is not correct. if the consumption of 1991 is more than coal mined in 1991 it is sufficient to explain the scenario. no need for consumption of 1991 to be more than consumption of 1990(it maybe true but not necessary that it MUST be true). if still in doubt try it with an example and let me know your doubts. will try to help.

Dude no need to thank me for the kudos. You deserved it actually when you explained the question with an example. You keep explaining like this and I'll keep sending my gestures.

Ok ..I got your point when you say that " it maybe true but not necessary that it MUST be true". Here's an example to prove this one.

1990 :
Coal Mined = 10kg
Coal consumed = 8kg
Coal reserve= 2 kg

1991 :
Coal Mined = 2kg
Coal consumed = 3.5kg
Coal reserve= 0.5 kg (considerably less than 1990 as mentioned in the question)

Hence, it is not necessarily true that coal consumption of 1991 was greater than that of 1990. However, the point that coal consumed in 1991 is ALWAYS greater than the coal mined in 1991 hold true EVERY TIME.

Explained it for anyone who might be interested in this post.

Cheers,
-V

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Re: Official LSAC Sample Test Quest Coal Mining and consumption [#permalink]

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03 Feb 2011, 07:29
good one vineet474.
now it is clear as day.
here is your first kudos...a little encouragement
looking forward to seeing your discussions and explanations in the coming days
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Re: Official LSAC Sample Test Quest Coal Mining and consumption   [#permalink] 03 Feb 2011, 07:29

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