Last visit was: 19 Nov 2025, 03:28 It is currently 19 Nov 2025, 03:28
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
605-655 Level|   Logical Flaw|            
User avatar
aimkp
Joined: 24 Aug 2010
Last visit: 30 Mar 2022
Posts: 73
Own Kudos:
292
 [46]
Given Kudos: 4
Products:
GMAT 1: 630 Q48 V28
Posts: 73
Kudos: 292
 [46]
6
Kudos
Add Kudos
40
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
mailnavin1
Joined: 24 Jul 2009
Last visit: 04 Aug 2012
Posts: 119
Own Kudos:
356
 [5]
Given Kudos: 30
Status:swimming against the current
Location: Chennai, India
Concentration: Finance
Posts: 119
Kudos: 356
 [5]
3
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,379
Own Kudos:
778,192
 [2]
Given Kudos: 99,977
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,379
Kudos: 778,192
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
General Discussion
User avatar
gmatin2011
Joined: 18 Nov 2010
Last visit: 02 Mar 2017
Posts: 16
Own Kudos:
Given Kudos: 24
Location: Richmond VA
Schools:ISB, IIMA (PGPX), IIMB (EMBA) & IIMC..
Posts: 16
Kudos: 6
Kudos
Add Kudos
Bookmarks
Bookmark this Post
aimkp
A gas tax of one cent per gallon would raise one billion dollars per year at current consumption rates. Since a tax of fifty cents per gallon would therefore raise fifty billion dollars per year, it seems a perfect way to deal with the federal budget deficit. This tax would have the additional advantage that the resulting drop in the demand for gasoline would be ecologically sound and would keep our country from being too dependent on foreign oil producers.
Which one of the following most clearly identifies an error in the author‟s reasoning?
(A) The author cites irrelevant data.
(B) The author relies on incorrect current consumption figures.
(C) The author makes incompatible assumptions.
(D) The author mistakes an effect for a cause.
(E) The author appeals to conscience rather than reason.

CONFUSE b\w A & C

IMO C.

In this CR, I see the options as,
A - Cannot say that author cites irrelevant data - Increase in price by 1 cent will result in x amount. Increase in price by 50x cent will result in 50x amount - I see this is relevant. Also, price rise will reduce usage is also relevant. - Incorrect
B - Cannot say this.. - Incorrect
C - Assumptions are wrong - Even a 1 cent increase will reduce consumption, at the same time 50 cent increase will not reduce consumption. So the author may not be able to comment on the consumption and ecological point.
D - I initially thought of this - but later realized wrong - Incorrect.
E - Incorrect.
User avatar
arps
Joined: 18 Dec 2011
Last visit: 13 Jul 2012
Posts: 42
Own Kudos:
579
 [1]
Given Kudos: 113
Posts: 42
Kudos: 579
 [1]
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Reasoning for C:

Assumption 1: When Tax increases, the consumption remaining the same, the overall Tax collected would increase and hence the budget deficit issue resolved.

If consumption reduces, even though the Tax per Unit has increases there is no guarantee, the overall Tax will increase.

Assumption 2: When Tax increases, the consumption will reduce and hence the use of fuel and our dependency on other countries for fuel will deduce.

Assumption-1 and Assumption-2 are incomparable.
User avatar
soumens
Joined: 05 Sep 2012
Last visit: 21 Jun 2013
Posts: 41
Own Kudos:
83
 [2]
Given Kudos: 17
Posts: 41
Kudos: 83
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
aimkp
A gas tax of one cent per gallon would raise one billion dollars per year at current consumption rates. Since a tax of fifty cents per gallon would therefore raise fifty billion dollars per year, it seems a perfect way to deal with the federal budget deficit. This tax would have the additional advantage that the resulting drop in the demand for gasoline would be ecologically sound and would keep our country from being too dependent on foreign oil producers.
Which one of the following most clearly identifies an error in the author‟s reasoning?
(A) The author cites irrelevant data.
(B) The author relies on incorrect current consumption figures.
(C) The author makes incompatible assumptions.
(D) The author mistakes an effect for a cause.
(E) The author appeals to conscience rather than reason.

CONFUSE b\w A & C

C seems to win by POE.
D is good distraction though, since mostly flaw questions mess up with cause and effect. But on close observation we can see that the cause and effect are not reversed.
Increase in taxes causes increased federal revenue.
Increase in taxes may cause people to decrease gasoline consumption.
Hence cause and effect are correctly stated.
User avatar
Archit143
Joined: 21 Sep 2012
Last visit: 20 Sep 2016
Posts: 721
Own Kudos:
Given Kudos: 70
Status:Final Lap Up!!!
Affiliations: NYK Line
Location: India
GMAT 1: 410 Q35 V11
GMAT 2: 530 Q44 V20
GMAT 3: 630 Q45 V31
GPA: 3.84
WE:Engineering (Transportation)
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Author seems to assume to polar opposite aspects of an effect.
First he considers with increase in tax budget deficit will decrease ie. he assumes people will continue buying at the same rate as they are buying now.
Second is With increase in tax , people will consume less gas and hence therefore decrease the foreign dependency on the gas..
Hence, for the same cause he assumes to polar opposite assumptions.

Hence the answer is C.
User avatar
JarvisR
Joined: 05 Nov 2012
Last visit: 05 Jan 2017
Posts: 337
Own Kudos:
4,900
 [3]
Given Kudos: 606
Concentration: Technology, Other
Products:
2
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
A gas tax of one cent per gallon would raise one billion dollars per year at current consumption rates. Since a tax of fifty cents per gallon would therefore raise fifty billion dollars per year, it seems a perfect way to deal with the federal budget deficit.
Assumption#1: The price increase would not decrease the demand.

This tax would have the additional advantage that the resulting drop in the demand for gasoline would be ecologically sound and would keep our country from being too dependent on foreign oil producers.
Assumption#1: There will be decrease in the demand.

Which one of the following most clearly identifies an error in the author‟s reasoning?

(A) The author cites irrelevant data.

(B) The author relies on incorrect current consumption figures.

(C) The author makes incompatible assumptions.

(D) The author mistakes an effect for a cause.

(E) The author appeals to conscience rather than reason.
avatar
shriramvelamuri
Joined: 27 Dec 2013
Last visit: 29 Jun 2016
Posts: 162
Own Kudos:
Given Kudos: 113
Posts: 162
Kudos: 137
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The answer C is perfect here. The thought process is as follows.

1. Option A: An irrelevant data is clearly irrelevant to this question

2. Option B: We do not what the current or the old consumption figures, hence irrelevant.

3. Option E: Appeals to conscience rather than reason. This option is irrelevant or beyond the scope.

Left are C and D.

C: Author make incorrect assumptions- [Keep]- reasoning being... as the demand for gasoline decreases, then people would start using fewer liters of gas and hence less revenue generation. Goal unachived.

D: Option D: May be kind of true, but what is effect and what is the cause? Out of scope.

souvik101990
A gas tax of one cent per gallon would raise one billion dollars per year at current consumption rates. Since a tax of fifty cents per gallon would therefore raise fifty billion dollars per year, it seems a perfect way to deal with the federal budget deficit. This tax would have the additional advantage that the resulting drop in the demand for gasoline would be ecologically sound and would keep our country from being too dependent on foreign oil producers.

Which one of the following most clearly identifies an error in the author‟s reasoning?

(A) The author cites irrelevant data.

(B) The author relies on incorrect current consumption figures.

(C) The author makes incompatible assumptions.

(D) The author mistakes an effect for a cause.

(E) The author appeals to conscience rather than reason.
User avatar
tarunk31
Joined: 25 Feb 2014
Last visit: 20 Jul 2022
Posts: 181
Own Kudos:
Given Kudos: 147
GMAT 1: 720 Q50 V38
Products:
GMAT 1: 720 Q50 V38
Posts: 181
Kudos: 462
Kudos
Add Kudos
Bookmarks
Bookmark this Post
C is best.


Plan: At current consumption rate, a tax of fifty cents per gallon would raise fifty billion dollars per year
Goal: deal with the federal budget deficit

Assumption: consumption remains same.

Additional advantage: resulting drop in the demand for gasoline would be ecologically sound and would keep our country from being too dependent on foreign oil producers. This advantage will contradict the assumption as decrease in demand means decrease in consumption and hence decrease in revenues. So plan won't meet the goal.

Hence, C
User avatar
mvictor
User avatar
Board of Directors
Joined: 17 Jul 2014
Last visit: 14 Jul 2021
Posts: 2,124
Own Kudos:
Given Kudos: 236
Location: United States (IL)
Concentration: Finance, Economics
GMAT 1: 650 Q49 V30
GPA: 3.92
WE:General Management (Transportation)
Products:
GMAT 1: 650 Q49 V30
Posts: 2,124
Kudos: 1,263
Kudos
Add Kudos
Bookmarks
Bookmark this Post
souvik101990
A gas tax of one cent per gallon would raise one billion dollars per year at current consumption rates. Since a tax of fifty cents per gallon would therefore raise fifty billion dollars per year, it seems a perfect way to deal with the federal budget deficit. This tax would have the additional advantage that the resulting drop in the demand for gasoline would be ecologically sound and would keep our country from being too dependent on foreign oil producers.

the conclusion here:
GT of 50c - perfect way to deal with FBD.
this will lead to lower demand and thus, preserve the nature and reduce the dependence on foreign oil.

the flaw here is that the author makes 2 incompatible assumptions. it is mentioned "current consumption rates", thus, if the demand decreases, there is NO WAY to make 50B $ from the tax.

Which one of the following most clearly identifies an error in the author‟s reasoning?

(A) The author cites irrelevant data.
we cannot say that.

(B) The author relies on incorrect current consumption figures.
current consumption is not at issue here.

(C) The author makes incompatible assumptions.
exactly! gvt wants to make 50B $ (at current consumption), while wanting to decrease the demand.

(D) The author mistakes an effect for a cause.
what is the effect? dropped demand? what is the cause? 50b $? can't figure out which is which, and C is way better than this one.

(E) The author appeals to conscience rather than reason.
no, he does reason, stating facts!!! but the way of thinking is flawed.
User avatar
abhishekdadarwal2009
Joined: 04 Sep 2015
Last visit: 07 Dec 2022
Posts: 530
Own Kudos:
Given Kudos: 123
Location: India
WE:Information Technology (Computer Software)
Products:
Posts: 530
Kudos: 476
Kudos
Add Kudos
Bookmarks
Bookmark this Post
A gas tax of one cent per gallon would raise one billion dollars per year at current consumption rates. Since a tax of fifty cents per gallon would therefore raise fifty billion dollars per year, it seems a perfect way to deal with the federal budget deficit. This tax would have the additional advantage that the resulting drop in the demand for gasoline would be ecologically sound and would keep our country from being too dependent on foreign oil producers.

Which one of the following most clearly identifies an error in the author's reasoning?


(A) The author cites irrelevant data.
whether the data is irrelevant is not correct point because the data provided is not the basis for reaching the conclusion.

(B) The author relies on incorrect current consumption figures.
we don't know whether if the figures are wrong or not.

(C) The author makes incompatible assumptions. correct answer

(D) The author mistakes an effect for a cause. the cause and effect case is not true in our scenario.

(E) The author appeals to conscience rather than reason. clearly out of scope.
User avatar
ravigupta2912
User avatar
Current Student
Joined: 26 May 2019
Last visit: 16 Feb 2025
Posts: 726
Own Kudos:
Given Kudos: 84
Location: India
GMAT 1: 650 Q46 V34
GMAT 2: 720 Q49 V40
GPA: 2.58
WE:Consulting (Consulting)
Products:
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Between C and B,

B would be wrong if the figure of 1B would be incorrect or there would be something to suggest that no drop in demand.

C is correct because the author citing the 1B additional tax revenue assumes that a similar pattern (say a liner demand curve) would hold. However, in reality the demand curve could fall exponentially for all we know.

Hence the assumption to travel to 50B figure from 1B figure is suspect.

Answer C

Posted from my mobile device
User avatar
Raman109
Joined: 17 Aug 2009
Last visit: 28 Jul 2025
Posts: 805
Own Kudos:
Given Kudos: 33
Posts: 805
Kudos: 170
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Understanding the argument -
A gas tax of one cent per gallon would raise one billion dollars per year at current consumption rates. - Premise/Opinion.
Since a tax of fifty cents per gallon would raise fifty billion dollars per year, it seems a perfect way to deal with the federal budget deficit. - Premise + opinion. But the premise is derived from the earlier premise. So the author assumes that if we raise the gas tax by one cent, we can raise 1 Bn; likewise, raising it to 50, 75, or 100 will lead to 50 bn, 75 bn, or 100 bn, respectively. So, the author is assuming that the consumption pattern will stay the same. What if the consumption reduces, then after increasing by 50 cents, it may for example lead to just two bn instead of 50? So, the author has made this assumption here.

Conclusion - "It seems to be a perfect way to deal with the federal budget deficit."

This tax would have the additional advantage that the resulting drop in the demand for gasoline would be ecologically sound and would keep our country from being too dependent on foreign oil producers. - ok, now it talks about additional benefits to strengthen our conclusion, which is "it seems a perfect way to deal with the federal budget deficit"
Drop-in demand for Gasoline would be
1. Ecologically sound
2. Reduce dependence on foreign oil.

So now it says that the demand will drop. Ok. So, earlier, we assumed that demand would remain the same. Then, we cited additional benefits to strengthen our conclusion that the demand would reduce, which contradicts what C highlights. The word "incompatibility" because, in conclusion, "it seems a perfect way to deal with the federal budget deficit." First, we assumed there would be no drop in consumption, but then we added a strengthening premise that there would be a drop in consumption. So, the flaw is that this assumption is incompatible with the premises stated in the argument.

Option Elimination. -

(A) The author cites irrelevant data. - No. Facts respected.

(B) The author relies on incorrect current consumption figures. - No. Facts respected.

(C) The author makes incompatible assumptions. - ok.

(D) The author mistakes an effect for a cause. - No. The effect of "reduction in Federal Deficit" is not mistaken as a cause that is not mentioned in the argument. An increase in tax collision can lead to a reduction in the Federal Deficit, but no specific cause of the Federal Deficit is stated in the argument.

(E) The author appeals to conscience rather than reason. - out of scope.
User avatar
Krishnahelps
Joined: 15 Nov 2020
Last visit: 10 Sep 2025
Posts: 134
Own Kudos:
Given Kudos: 1,686
Schools: ISB '27 (A)
Schools: ISB '27 (A)
Posts: 134
Kudos: 33
Kudos
Add Kudos
Bookmarks
Bookmark this Post
How is the line that the demand will decrease an assumption when it is clearly stated? An assumption is something that is assumed and not clearly stated. Please guide here.
Moderators:
GMAT Club Verbal Expert
7445 posts
GMAT Club Verbal Expert
234 posts
188 posts