Problem Set
1. For a ten-month period, the total monthly sales of new cars within the country of Calistan remained constant. During this period the monthly sales of new cars manufactured by Marvel Automobile Company doubled, and its share of the new car market within Calistan increased correspondingly. At the end of this period, emission standards were imposed on new cars sold within Calistan. During the three months following this imposition, Marvel Automobile Company’s share of the Calistan market declined substantially even though its monthly sales within Calistan remained constant at the level reached in
the last month of the ten-month period.
If the statements above are true, which one of the
following CANNOT be true?
(A) The total monthly sales within Calistan of new
cars by companies other than Marvel
Automobile Company decreased over the
three months following the imposition of the
emission standards.
(B) Over the three months before the imposition of
the emission standards, the combined market
share of companies other than Marvel
Automobile Company selling new cars in
Calistan decreased.
(C) If the emission standards had not been imposed,
Marvel Automobile Company would have
lost an even larger share of the number of
new cars sold in Calistan than, in fact, it did.
(D) A decrease in the total monthly sales of new
cars within Calistan will occur if the emission
standards remain in effect.
(E) Since the imposition of the emission standards,
Marvel Automobile Company’s average
profit on each new car sold within Calistan
has increased.
2. Two things are true of all immoral actions. First, if they are performed in public, they offend public sensibilities. Second, they are accompanied by feelings of guilt.
If all the statements above are true, then which one of
the following must be false?
(A) Some immoral actions that are not performed in
public are not accompanied by feelings of
guilt.
(B) Immoral actions are wrong solely by virtue of
being accompanied by feelings of guilt.
(C) Some actions that offend public sensibilities if
they are performed in public are not
accompanied by feelings of guilt.
(D) Some actions that are accompanied by feelings
of guilt are not immoral, even if they
frequently offend public sensibilities.
(E) Every action performed in public that is
accompanied by feelings of guilt is immoral.
Answer Key
All answer keys in this book indicate the source of the question by giving the month and year the LSAT
was originally administered, the Logical Reasoning section number, and the question number within that
section. Each LSAT has two Logical Reasoning sections, and so the Section 1 and Section 2 designators
will refer to the first or second Logical Reasoning section in the test, not the physical section number of the
booklet.
Question #1. Cannot-#%. June 2000 LSAT, Section 1, #15. The correct answer choice is (A)
This question is a repeat of a question that appeared on the March 1985 LSAT (remember, on the LSAT
past is prologue). The topic of the original question was also the car market, but the company in question
was called Superb Automobile. Several of the answer choices, including the correct answer, were virtually
identical to the answers in this problem.
Let us first review the facts given in the stimulus:
Statement: For a ten-month period, the total monthly sales of new cars within the country of
Calistan remained constant.
The wording of this statement should alert you that numbers and percentages in the form of market
share (“monthly sales...remained constant”) may be an issue in this problem. Note that the
statement is a simple fact; no explanation is given for why the total sales stayed constant.
Statement: During this period the monthly sales of new cars manufactured by Marvel Automobile
Company doubled, and its share of the new car market within Calistan increased
correspondingly.
If total monthly sales of new cars remains constant and Marvel’s sales doubled, then Marvel’s share
of the new car market must also have doubled. Again, no explanation for Marvel’s increase is
given; the increase is just stated as a fact.
Statement: At the end of this period, emission standards were imposed on new cars sold within
Calistan.
Imposing new emission standards serves as a chronology marker in this stimulus. Again, no
explanation is given for why the new standards were imposed.
Statement: During the three months following this imposition, Marvel Automobile Company’s
share of the Calistan market declined substantially even though its monthly sales within
Calistan remained constant at the level reached in the last month of the ten-month
period.
This sentence is the key to the stimulus. From a numbers and percentages standpoint, we are given
two pieces of related information: during the three months after the emissions standards were
imposed, Marvel’s monthly sales of new cars within Calistan remained constant at the prestandards
level, and at the same time Marvel’s share of the market declined. From the discussion in
Chapter Seventeen, we know that if sales remain constant but the share represented by those sales
decreased, then the overall sales in the market must have increased. For example:
pre-Standards post-Standards
Marvel’s Monthly New Car Sales 10 10
Total Monthly New Car Sales in Calistan 100 200
Marvel’s Market Share 10% 5%
The other important part of this sentence is what is not said. No cause is given for Marvel’s decline,
and you cannot assume that the new emissions standards are the cause of the decline (causal
indicators are needed to convey causality, and none are present in this stimulus). Remember, one
error of causal reasoning is to assume that because two things occur in sequence that one caused
the other. There could be many different explanations for Marvel’s decline other than the new
emission standards. For example, Marvel could have raised their car prices or perhaps Marvel
received some negative publicity about the quality of their cars. Regardless, the problem is clearly
designed to test whether you will fall into the trap of assuming that the new emission standards
caused Marvel to lose market share, so read carefully and do not fill in the “spaces” in the stimulus.
Answer choice (A): This is the correct answer. As shown in the discussion of the last sentence of the
stimulus, in the three months after the imposition of the emissions standards, the total monthly car sales in
Calistan must have risen, and since Marvel’s monthly car sales remained constant, we can conclude that
the sales of other car makers must have risen. Since this answer claims they decreased, this answer cannot
be true and is correct.
Answer choice (B): This answer is possibly true. The stimulus indicates that Marvel doubled sales and
market share in the ten months prior to the imposition of the emissions standards, and it is possible that in
the three months prior to the implementation of the new standards the market share of the other companies
decreased.
Some students look at this answer and assume that it must be true based on the first two sentences of the
stimulus. But that judgment assumes that Marvel’s growth during the ten-month period was constant, a
circumstance never stated by the author. It would be consistent with the stimulus if Marvel doubled sales in
the first month and then remained constant for the remaining nine months.
Answer choice (C): No reason is given for Marvel’s loss of market share (or alternately, the increased sales
of other manufacturers), so it is possible that the new emission standards actually decreased Marvel’s loss
of market share (or alternately, the emission standards limited the increase in sales of the other
manufacturers). Remember, no explanation is given for the situation after the imposition of the emission
standards, so whatever happened in the absence of the standards could always be true.
Answer choice (D): This answer could occur because Calistan’s future car sales could fall due to a variety
of causes (including the emission standards). This is true regardless of whether the emissions standards
remain in force because we know nothing of the effect of the standards.
Answer choice (E): No information is given about profit in the stimulus, so this answer choice could be
true.
Question #2. Cannot-SN. October 2003 LSAT, Section 1, #7. The correct answer choice is (A)
At this point you should have memorized the Primary Objectives and know how to apply them to the
problem. This question is an excellent example of Primary Objective #“4R: ead closely and know
precisely what the author said. Do not generalize!”
Most students make the mistake of thinking that both statements about immoral actions refer to actions
performed in public, but this is incorrect. Instead, only the first statement refers to actions in public; the
second statement refers to all immoral actions, public or not. Take a look at the two statements:
The first statement regarding immoral actions indicates that “if they are performed in public, they
offend public sensibilities.” The correct diagram for this statement is:
IP = immoral actions performed in public
O = offend public sensibilities
IP----------> O
The relationship above is restricted to public performances. No information is given about nonpublic
performances.
The next statement in the stimulus is “second, they are accompanied by feelings of guilt.” This
statement can cause problems because most student assume that the “they” refers to immoral
actions performed in public. But read the stimulus carefully—the first sentence states that two
things are true of immoral actions, and the “they” in the last sentence refers to those actions in the
first sentence. Because the last sentence does not reference actions in public, it is a broader
statement that addresses all immoral actions:
I = immoral actions
G = accompanied by feelings of guilt
I-----------> G
Thus, the two conditional statements in the stimulus do not have the same sufficient condition.
Again, read carefully in order to avoid the error of assuming the two statements reference the same
condition.
Answer choice (A): This is the correct answer. Answer choice (A) is correct because any immoral action is
accompanied by feelings of guilt, and (A) improperly tries to assert that some immoral actions are not
accompanied by feelings of guilt. Note how this answer plays off the second statement—the exact
statement that many students are likely to misunderstand. If you interpret the second statement to apply to
public actions, you will mistakenly think answer choice (A) could occur.
Answer choice (B): The stimulus does not address the “wrongness” of immoral actions. Thus, this answer
could possibly be true and is therefore incorrect.
Answer choice (C): This answer is tricky. Look carefully at the wording of the answer—is immorality
mentioned? No, it is not, and thus neither sufficient condition in the stimulus can apply. The statement in
this answer choice is possible because a public action that offends public sensibilities does not have to be
an immoral action, and so a public action that offends public sensibilities does not have to be accompanied
by feelings of guilt.
For the purposes of discussion, say that the public action in question is flag burning. Such an action
performed in public could offend the public, but since we do not know if it immoral according to the
answer, the flag burner does not have to experience feelings of guilt. This conforms to the scenario
described in answer choice (C).
Answer choice (D): This answer choice tests your knowledge a Mistaken Reversal. Remember, any
Mistaken Reversal is an error because it is not certain that the sufficient condition must occur when the
necessary condition occurs. So, if the necessary condition occurs, the sufficient condition may or may not
occur. This answer states that the necessary condition of the second statement occurs and that the sufficient
does not. This outcome is possible under any single-arrow conditional scenario. In concrete terms, just
because some actions are accompanied by feelings of guilt does not mean they are immoral, so this answer
choice could occur and hence is wrong.
Answer choice (E): This answer tests the flip side of possibilities that could occur under a conditional
statement. In this situation, the necessary condition of the second statement occurs and the sufficient
condition also occurs. Since a Mistaken Reversal might be true unless otherwise stated, this answer could
occur and is incorrect.
Answer choices (D) and (E) present a dynamic one-two punch: answer choice (D) tests to see if you
understand that the occurrence of the necessary condition does not automatically lead to the occurrence of
the sufficient condition, and answer choice (E) tests to see if you understand that the occurrence of the
necessary condition could lead to the occurrence of the sufficient condition.
1. For a ten-month period, the total monthly sales of new cars within the country of Calistan remained constant. During this period the monthly sales of new cars manufactured by Marvel Automobile Company doubled, and its share of the new car market within Calistan increased correspondingly. At the end of this period, emission standards were imposed on new cars sold within Calistan. During the three months following this imposition, Marvel Automobile Company’s share of the Calistan market declined substantially even though its monthly sales within Calistan remained constant at the level reached in
the last month of the ten-month period.
If the statements above are true, which one of the
following CANNOT be true?
(A) The total monthly sales within Calistan of new
cars by companies other than Marvel
Automobile Company decreased over the
three months following the imposition of the
emission standards.
(B) Over the three months before the imposition of
the emission standards, the combined market
share of companies other than Marvel
Automobile Company selling new cars in
Calistan decreased.
(C) If the emission standards had not been imposed,
Marvel Automobile Company would have
lost an even larger share of the number of
new cars sold in Calistan than, in fact, it did.
(D) A decrease in the total monthly sales of new
cars within Calistan will occur if the emission
standards remain in effect.
(E) Since the imposition of the emission standards,
Marvel Automobile Company’s average
profit on each new car sold within Calistan
has increased.
2. Two things are true of all immoral actions. First, if they are performed in public, they offend public sensibilities. Second, they are accompanied by feelings of guilt.
If all the statements above are true, then which one of
the following must be false?
(A) Some immoral actions that are not performed in
public are not accompanied by feelings of
guilt.
(B) Immoral actions are wrong solely by virtue of
being accompanied by feelings of guilt.
(C) Some actions that offend public sensibilities if
they are performed in public are not
accompanied by feelings of guilt.
(D) Some actions that are accompanied by feelings
of guilt are not immoral, even if they
frequently offend public sensibilities.
(E) Every action performed in public that is
accompanied by feelings of guilt is immoral.
Answer Key
All answer keys in this book indicate the source of the question by giving the month and year the LSAT
was originally administered, the Logical Reasoning section number, and the question number within that
section. Each LSAT has two Logical Reasoning sections, and so the Section 1 and Section 2 designators
will refer to the first or second Logical Reasoning section in the test, not the physical section number of the
booklet.
Question #1. Cannot-#%. June 2000 LSAT, Section 1, #15. The correct answer choice is (A)
This question is a repeat of a question that appeared on the March 1985 LSAT (remember, on the LSAT
past is prologue). The topic of the original question was also the car market, but the company in question
was called Superb Automobile. Several of the answer choices, including the correct answer, were virtually
identical to the answers in this problem.
Let us first review the facts given in the stimulus:
Statement: For a ten-month period, the total monthly sales of new cars within the country of
Calistan remained constant.
The wording of this statement should alert you that numbers and percentages in the form of market
share (“monthly sales...remained constant”) may be an issue in this problem. Note that the
statement is a simple fact; no explanation is given for why the total sales stayed constant.
Statement: During this period the monthly sales of new cars manufactured by Marvel Automobile
Company doubled, and its share of the new car market within Calistan increased
correspondingly.
If total monthly sales of new cars remains constant and Marvel’s sales doubled, then Marvel’s share
of the new car market must also have doubled. Again, no explanation for Marvel’s increase is
given; the increase is just stated as a fact.
Statement: At the end of this period, emission standards were imposed on new cars sold within
Calistan.
Imposing new emission standards serves as a chronology marker in this stimulus. Again, no
explanation is given for why the new standards were imposed.
Statement: During the three months following this imposition, Marvel Automobile Company’s
share of the Calistan market declined substantially even though its monthly sales within
Calistan remained constant at the level reached in the last month of the ten-month
period.
This sentence is the key to the stimulus. From a numbers and percentages standpoint, we are given
two pieces of related information: during the three months after the emissions standards were
imposed, Marvel’s monthly sales of new cars within Calistan remained constant at the prestandards
level, and at the same time Marvel’s share of the market declined. From the discussion in
Chapter Seventeen, we know that if sales remain constant but the share represented by those sales
decreased, then the overall sales in the market must have increased. For example:
pre-Standards post-Standards
Marvel’s Monthly New Car Sales 10 10
Total Monthly New Car Sales in Calistan 100 200
Marvel’s Market Share 10% 5%
The other important part of this sentence is what is not said. No cause is given for Marvel’s decline,
and you cannot assume that the new emissions standards are the cause of the decline (causal
indicators are needed to convey causality, and none are present in this stimulus). Remember, one
error of causal reasoning is to assume that because two things occur in sequence that one caused
the other. There could be many different explanations for Marvel’s decline other than the new
emission standards. For example, Marvel could have raised their car prices or perhaps Marvel
received some negative publicity about the quality of their cars. Regardless, the problem is clearly
designed to test whether you will fall into the trap of assuming that the new emission standards
caused Marvel to lose market share, so read carefully and do not fill in the “spaces” in the stimulus.
Answer choice (A): This is the correct answer. As shown in the discussion of the last sentence of the
stimulus, in the three months after the imposition of the emissions standards, the total monthly car sales in
Calistan must have risen, and since Marvel’s monthly car sales remained constant, we can conclude that
the sales of other car makers must have risen. Since this answer claims they decreased, this answer cannot
be true and is correct.
Answer choice (B): This answer is possibly true. The stimulus indicates that Marvel doubled sales and
market share in the ten months prior to the imposition of the emissions standards, and it is possible that in
the three months prior to the implementation of the new standards the market share of the other companies
decreased.
Some students look at this answer and assume that it must be true based on the first two sentences of the
stimulus. But that judgment assumes that Marvel’s growth during the ten-month period was constant, a
circumstance never stated by the author. It would be consistent with the stimulus if Marvel doubled sales in
the first month and then remained constant for the remaining nine months.
Answer choice (C): No reason is given for Marvel’s loss of market share (or alternately, the increased sales
of other manufacturers), so it is possible that the new emission standards actually decreased Marvel’s loss
of market share (or alternately, the emission standards limited the increase in sales of the other
manufacturers). Remember, no explanation is given for the situation after the imposition of the emission
standards, so whatever happened in the absence of the standards could always be true.
Answer choice (D): This answer could occur because Calistan’s future car sales could fall due to a variety
of causes (including the emission standards). This is true regardless of whether the emissions standards
remain in force because we know nothing of the effect of the standards.
Answer choice (E): No information is given about profit in the stimulus, so this answer choice could be
true.
Question #2. Cannot-SN. October 2003 LSAT, Section 1, #7. The correct answer choice is (A)
At this point you should have memorized the Primary Objectives and know how to apply them to the
problem. This question is an excellent example of Primary Objective #“4R: ead closely and know
precisely what the author said. Do not generalize!”
Most students make the mistake of thinking that both statements about immoral actions refer to actions
performed in public, but this is incorrect. Instead, only the first statement refers to actions in public; the
second statement refers to all immoral actions, public or not. Take a look at the two statements:
The first statement regarding immoral actions indicates that “if they are performed in public, they
offend public sensibilities.” The correct diagram for this statement is:
IP = immoral actions performed in public
O = offend public sensibilities
IP----------> O
The relationship above is restricted to public performances. No information is given about nonpublic
performances.
The next statement in the stimulus is “second, they are accompanied by feelings of guilt.” This
statement can cause problems because most student assume that the “they” refers to immoral
actions performed in public. But read the stimulus carefully—the first sentence states that two
things are true of immoral actions, and the “they” in the last sentence refers to those actions in the
first sentence. Because the last sentence does not reference actions in public, it is a broader
statement that addresses all immoral actions:
I = immoral actions
G = accompanied by feelings of guilt
I-----------> G
Thus, the two conditional statements in the stimulus do not have the same sufficient condition.
Again, read carefully in order to avoid the error of assuming the two statements reference the same
condition.
Answer choice (A): This is the correct answer. Answer choice (A) is correct because any immoral action is
accompanied by feelings of guilt, and (A) improperly tries to assert that some immoral actions are not
accompanied by feelings of guilt. Note how this answer plays off the second statement—the exact
statement that many students are likely to misunderstand. If you interpret the second statement to apply to
public actions, you will mistakenly think answer choice (A) could occur.
Answer choice (B): The stimulus does not address the “wrongness” of immoral actions. Thus, this answer
could possibly be true and is therefore incorrect.
Answer choice (C): This answer is tricky. Look carefully at the wording of the answer—is immorality
mentioned? No, it is not, and thus neither sufficient condition in the stimulus can apply. The statement in
this answer choice is possible because a public action that offends public sensibilities does not have to be
an immoral action, and so a public action that offends public sensibilities does not have to be accompanied
by feelings of guilt.
For the purposes of discussion, say that the public action in question is flag burning. Such an action
performed in public could offend the public, but since we do not know if it immoral according to the
answer, the flag burner does not have to experience feelings of guilt. This conforms to the scenario
described in answer choice (C).
Answer choice (D): This answer choice tests your knowledge a Mistaken Reversal. Remember, any
Mistaken Reversal is an error because it is not certain that the sufficient condition must occur when the
necessary condition occurs. So, if the necessary condition occurs, the sufficient condition may or may not
occur. This answer states that the necessary condition of the second statement occurs and that the sufficient
does not. This outcome is possible under any single-arrow conditional scenario. In concrete terms, just
because some actions are accompanied by feelings of guilt does not mean they are immoral, so this answer
choice could occur and hence is wrong.
Answer choice (E): This answer tests the flip side of possibilities that could occur under a conditional
statement. In this situation, the necessary condition of the second statement occurs and the sufficient
condition also occurs. Since a Mistaken Reversal might be true unless otherwise stated, this answer could
occur and is incorrect.
Answer choices (D) and (E) present a dynamic one-two punch: answer choice (D) tests to see if you
understand that the occurrence of the necessary condition does not automatically lead to the occurrence of
the sufficient condition, and answer choice (E) tests to see if you understand that the occurrence of the
necessary condition could lead to the occurrence of the sufficient condition.
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