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.
amount of coal
-
- Legendary Member
- Posts: 2326
- Joined: Mon Jul 28, 2008 3:54 am
- Thanked: 173 times
- Followed by:2 members
- GMAT Score:710
total available coal supplies
==
total amount mined- total amount consumed.
B,C,E are ruled out.
We are left with A & D
It can be either of A or D depending on which is constant.Here no data is given about whether the amt to be mined or the amt to be consumed between the years to be constant.that creates the dilema of opting A or D
Since it says they are not importing or exporting,somepoint of time their resources shall deplete.If teh rate of mining is constant then amt of coal mined in 1991 is less than 1990.
By that IMO A is stronger than D.
My vote goes to A
Iam damn eager to c the OA and comments!!1
==
total amount mined- total amount consumed.
B,C,E are ruled out.
We are left with A & D
It can be either of A or D depending on which is constant.Here no data is given about whether the amt to be mined or the amt to be consumed between the years to be constant.that creates the dilema of opting A or D
Since it says they are not importing or exporting,somepoint of time their resources shall deplete.If teh rate of mining is constant then amt of coal mined in 1991 is less than 1990.
By that IMO A is stronger than D.
My vote goes to A
Iam damn eager to c the OA and comments!!1
-
- Master | Next Rank: 500 Posts
- Posts: 189
- Joined: Thu Apr 03, 2008 2:03 pm
- Location: USA
- Thanked: 21 times
Has to be B ..You need to take care of cumulative amounts of coal .
A could be true but here point is 'must be true' answer. It could be that in 1990 less coal was mined but even less was consumed .. so you get more unconsumed coal left over than 1991..So A cant be must be true answer
A could be true but here point is 'must be true' answer. It could be that in 1990 less coal was mined but even less was consumed .. so you get more unconsumed coal left over than 1991..So A cant be must be true answer
-
- Legendary Member
- Posts: 2326
- Joined: Mon Jul 28, 2008 3:54 am
- Thanked: 173 times
- Followed by:2 members
- GMAT Score:710
-
- Newbie | Next Rank: 10 Posts
- Posts: 3
- Joined: Wed Aug 26, 2009 10:58 pm
- Location: Germany
I think it's B too.
In 31st Dec 1990 they have X and in 1991 they mine Y and spend Z. so in 31DEC91 they have X+Y-Z and it's smaller than X... hence Z must be greater than Y. or more coal consumed than mined in 1991.
In 31st Dec 1990 they have X and in 1991 they mine Y and spend Z. so in 31DEC91 they have X+Y-Z and it's smaller than X... hence Z must be greater than Y. or more coal consumed than mined in 1991.
-
- Master | Next Rank: 500 Posts
- Posts: 338
- Joined: Fri Apr 17, 2009 1:49 am
- Thanked: 9 times
- Followed by:3 members
IMO B .. took a lot of time
1990
mined consumed not consumed
100 30 70
now in 1991 this 70 will be carry forwarded
Mined consumed notconsumed
70+ 10 20 60
70+ 30 40 60
70 + 100 110 60
1990
mined consumed not consumed
100 30 70
now in 1991 this 70 will be carry forwarded
Mined consumed notconsumed
70+ 10 20 60
70+ 30 40 60
70 + 100 110 60
-
- Legendary Member
- Posts: 527
- Joined: Mon Jun 02, 2008 9:14 am
- Location: Atlanta
- Thanked: 17 times
-
- Legendary Member
- Posts: 869
- Joined: Wed Aug 26, 2009 3:49 pm
- Location: California
- Thanked: 13 times
- Followed by:3 members
- karthikpandian19
- Legendary Member
- Posts: 1665
- Joined: Thu Nov 03, 2011 7:04 pm
- Thanked: 165 times
- Followed by:70 members
From the argument how is that it is assumed the coal supplies are cumulative and not year on year basis.
Regards,
Karthik
The source of the questions that i post from JUNE 2013 is from KNEWTON
---If you find my post useful, click "Thank" ---
---Never stop until cracking GMAT---
Karthik
The source of the questions that i post from JUNE 2013 is from KNEWTON
---If you find my post useful, click "Thank" ---
---Never stop until cracking GMAT---
- GMATGuruNY
- GMAT Instructor
- Posts: 15539
- Joined: Tue May 25, 2010 12:04 pm
- Location: New York, NY
- Thanked: 13060 times
- Followed by:1906 members
- GMAT Score:790
By definition, the amount of coal AVAILABLE is equal to the TALLY at the end of the PREVIOUS year + THE INCREASE OR LOSS from the CURRENT year.ranell wrote: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.
At the end of 1990, TALLY = mined - consumed = x.
In order for the value of x to DECREASE in 1991, the tally in 1991 -- in other words, the value of (MINED IN 1991 - CONSUMED IN 1991) -- must be NEGATIVE.
Thus, it must be true that CONSUMED IN 1991 > MINED IN 1991, supporting answer choice B:
In Country Q, the amount of coal consumed in 1991 was greater than the amount of coal mined in 1991.
The correct answer is B.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
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.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
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.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
- karthikpandian19
- Legendary Member
- Posts: 1665
- Joined: Thu Nov 03, 2011 7:04 pm
- Thanked: 165 times
- Followed by:70 members
Mitch,
Each December 31 in Country Q, a tally ...., the total amount of coal that has been mined throughout the country but not consumed.
I was initially confused with the usage of BUT in this sentence, that i accounted that "consumption" must not be taken into account for the equation.
But as per the explanation, it functions as subtraction in the equation
Each December 31 in Country Q, a tally ...., the total amount of coal that has been mined throughout the country but not consumed.
I was initially confused with the usage of BUT in this sentence, that i accounted that "consumption" must not be taken into account for the equation.
But as per the explanation, it functions as subtraction in the equation
GMATGuruNY wrote:By definition, the amount of coal AVAILABLE is equal to the TALLY at the end of the PREVIOUS year + THE INCREASE OR LOSS from the CURRENT year.ranell wrote: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.
At the end of 1990, TALLY = mined - consumed = x.
In order for the value of x to DECREASE in 1991, the tally in 1991 -- in other words, the value of (MINED IN 1991 - CONSUMED IN 1991) -- must be NEGATIVE.
Thus, it must be true that CONSUMED IN 1991 > MINED IN 1991, supporting answer choice B:
In Country Q, the amount of coal consumed in 1991 was greater than the amount of coal mined in 1991.
The correct answer is B.
Regards,
Karthik
The source of the questions that i post from JUNE 2013 is from KNEWTON
---If you find my post useful, click "Thank" ---
---Never stop until cracking GMAT---
Karthik
The source of the questions that i post from JUNE 2013 is from KNEWTON
---If you find my post useful, click "Thank" ---
---Never stop until cracking GMAT---
-
- Master | Next Rank: 500 Posts
- Posts: 122
- Joined: Tue May 01, 2012 6:05 am
- Thanked: 3 times