We are looking for an answer that must be true, and anything that CBT, CBF or MBF is the wrong answer.

The stimulus tells us:

scientists estimate the mass of the comets by their brightness

the material of which Halley's comet reflects 60 times less light per unit of mass than had been previously thought.

The scientists assume that the mass of a comet will be directly proportional to its brightness (1:1). So, if it was double the mass then we would see double the brightness. So, if we were to measure the brightness of Halley's comet, we would be assuming that the brightness we measure will be proportional to the mass of the comet (1:1). But if the material that Halley's comet is made of reflects 60 times less light per unit of mass than previously thought then the mass of Halley's comet is 60 times greater than previously thought.

or as B puts it: previous estimates of the mass of Haley's comet were too low.

For evaluating question, we should be mindful of the type of argument being presented.

In this case, I would call this a "Rules: Application" type of argument.

Rule:

The World Bank's "Doing business" report ranks countries in terms of ease of doing business in them by assessing how difficult it would be for a hypothetical business to comply with regulations and pay taxes.

Applicaiton:

Since the last report came out, our government has drastically simplified tax filing for small and even mid-sized businesses. So our ranking will probably improve.

We can make sense of the right answer by being specific of what sort of evaluation we are meant to be making. So, to be more specific, of what kind of "evaluation" we are making I would rephrase the wording for this question as such:

The answer to which one of the following questions would help most in evaluating the finance minister's application of the rules set out in the World Bank's "Doing Business" report?

(D) is the right question to ask because the answer to it would help us assess whether the finance minister's prediction was made based on the appropriate application of the rules set out in the World Bank's "Doing Business" report.

Argument: Polls designed to discover the opinions of the national population would have less accurate results if census participation became voluntary because the participation rate in a voluntary system would be lower than in a mandatory one and census data needs to reflect the demographic characteristics of the national population.

Summary: Voluntary census would less accurately represent the national population than a mandatory one because a voluntary census would have lower participation rates than a mandatory one.

Assumption: different levels of participation would change the demographic characteristics of the dataset.

(C) the voluntary census data would differ in demographic characteristics from the mandatory census data

If we negate the NA, the argument should fall apart.

(C) negated: the voluntary census data would not differ in demographic characteristics from the mandatory census data

If the demographic characteristics of the two datasets are exactly the same, then one dataset would not be more or less accurate than the other.

Since the doctors deliberately stop the patient's life functions, then if these functions do not resume following the procedure, the medial team is technically guilty of manslaughter.

According to this argument, what key element qualifies it as manslaughter?

The fact that it was deliberate is what makes it manslaughter.

1) Subjects guessed correctly less than half of the time

2) if they guessed that the next image would always appear at the top, they would have been correct most of the time.

Inferences:

Most of the time, the image appears at the top according to (2). Therefore

subjects guessed the top less than half of the time according to (1).

Put these two inferences together and you get (D): some of the subjects guessed that the next image appears at the bottom of the computer screen but were incorrect.

Proof:

If most of the time, the image appears at the top and most of the time the subjects guessed incorrectly, then they must have at least sometimes guessed the bottom and been wrong.

We attack flawed questions by identifying the assumption made between the premise and conclusion.

Premise: Polls predict that the majority party, which supported the bill's passage, will lose more than a dozen seats in the upcoming election.

Conclusion: (Therefore) the recently passes highway bill is clearly very unpopular with voters.

Assumption: the majority party is losing seats in the upcoming election because they support the bill's passage.

(A) says the reasoning in the legislator's argument is flawed because it gives no reason to think that the predicted election outcome would be different if the majority party had not supported the bill.

In other words, the legislator assumes without warrant that the majority party's support for the bill is directly causing the predicted loss of seats in the election.

Flaw: We must assess what flawed assumption the author is making by identifying the way in which the author jumps from premise to conclusion and articulate why that is wrong.

Premise: Other survey results have confirmed one study which found that the more frequently people engaged in aerobic exercise, the lower their risk of lung disease tended to be.

Conclusion: (Therefore) Aerobic exercise has a significant beneficial effect on people's health.

Assumption: Correlation means causation. Correlation can be purely circumstantial. For instance, what if people who tend to engage in aerobic exercise are the same kind of people who are non-smokers?

CONCLUSION: Constantly repeating simple phrases does not provide extra help to children learning a language.

PREMISE: There are families in which no one speaks to babies using simple phrases, yet the children in these families master grammatical structure of their language just as well and as quickly as other children do.

Since there are children who master grammatical structure of their language just as well and as quickly as other children do without the use of simple phrases, constantly repeating simple phrases does not provide extra help to children learning a language.

NECESSARY ASSUMPTION: mastering the grammatical structure of a language is synonymous with learning a language.

NEGATE NECESSARY ASSUMPTION: mastering the grammatical structure of a language is not synonymous with learning a language.

If mastering the grammatical structure of a language is not synonymous with learning a language, then the fact that a child mastered the grammatical structure of a language without the using simple phrases does not prove that simple phrases do not provide extra help to children learning a language.

CONCLUSION: The fact that people can now clearly distinguish between sour, bitter, sweet, and salty is completely explained by people's use of taste to test for healthfulness of foods.

How?

PREMISE: (Because) Taste buds were the primary tool early humans used for testing foods and early humans recognized sweet foods and salty foods as meeting nutritional needs.

Flaw: the author clearly cites at least two means in which taste was used: test for poison and test for nutrition but insists there is only one explanation.

The question: Why do corrections to data tend to favor Jones's theory?

In any field and in any case, if we tend to find evidence in favor of a theory two things could be happening:

1. The theory is correct

2. People are gathering evidence based on the underlying assumption that the theory is correct. (Confirmation Bias: the tendency to search for, interpret, favor, and recall information in a way that confirms or supports one's prior beliefs or values.) So people are correcting data in a way that assumes that Jones's theory is correct.

CONCLUSION: Evidence indicates that citizens are becoming increasingly disconnected from the political system with each passing generation. (Generation)

How?

PREMISE: Voting records regularly show that people over 65 votes in the highest percentages while young adults are least likely to vote. (Age)

FLAW/ASSUMPTION TYPE: CONTROLS IN A MULTIVARIATE REGRESSION

Just because the younger group was less likely to vote than the older group does not necessarily mean that the younger the generation is, the less likely they are to vote. Why? Because for us to draw any worthy comparisons, all other discrepancies have to be controlled for. To draw an absolute conclusion, we have to control for all relative discrepancies, we cannot measure multiple variables simultaneously. Any dissimilarity between the groups has equal explanatory power for any discrepancy we observe. To measure any dissimilarities in absolute terms we have to control all other variables that make them dissimilar. If we are to make a comparison between generations (as the conclusion does) then we have to control for age, which the evidence fails to do. Otherwise, any discrepancy we observe in the two groups could be caused by age or the time they are living in.

CONCLUSION: Evidence indicates that citizens are becoming increasingly disconnected from the political system with each passing generation. (Generation)

How?

PREMISE: Voting records regularly show that people over 65 votes in the highest percentages while young adults are least likely to vote. (Age)

FLAW/ASSUMPTION TYPE: RELATIVE VS ABSOLUTE

Just because the younger group was less likely to vote than the older group does not necessarily mean that the younger the generation is, the less likely they are to vote. We cannot measure multiple discrepancies simultaneous and draw absolute measurements from them. Why? Because for us to draw any worthy comparisons, the things were are comparing have too comparable. Any dissimilarity between the groups has equal explanatory power for any discrepancy we observe. To measure any dissimilarities in absolute terms we have to control all other variables that make them dissimilar. If we are to make a comparison between generations (as the conclusion does) then we have to control for age, which the evidence fails to do. Otherwise, any discrepancy we observe in the two groups could be caused by age or the time they are living in.

CONCLUSION: The public evidently heeded the public health campaign which sought to limit the spread of influenza.

The argument being that the evidence clearly shows a causal relationship.

Why?

PREMISE: (Because) the incidence of influenza was much lower during those months (during the campaign) than experts had predicted.

Let's start with the obvious/sufficient assumption:

1. Correlation equals causation.

We have to show that (1) the correlation isn't merely circumstantial, (2) that the cause is not actually the effect, and (3) that there is not an alternative causal explanation.

The less obvious but necessary assumption:

2. Causal relationship actually exist

We need to establish that washing your hands and avoiding public spaces actually limits the spread of influenza. Otherwise, the argument falls apart.

The other, less obvious assumption is that what the experts predicted was accurate.

3. Belief/Knowledge vs Fact/Reality

We need to show that what the experts predicted was not merely an underestimation.

AC A strengthens the necessary assumption (2. Causal relationship actually exists.)

CONCLUSION: the mayor did not necessarily take a bribe even though the consultant that does business with the city paid for improvements to the mayor's vacation home.

Why?

PREMISE: (Because) the mayor said that he paid every bill for those improvements that was presented to him.

ASSUMPTION: The only expenses the mayor knew about were the ones presented to him in the form of a bill.

To attack an argument, we must weaken the validity of the assumption.

B) The mayor was aware that many of the bills were being presented the consultant rather than the mayor.

Translation #1

A) Valid→ Legit and Accepted

B) Legit → Was not reasonably believed to be said in jest.

Translation #2

A) Not legit or not accepted → not valid.

B) Reasonably believed to be said in jest→ not legit.

Answers:

A) Confuses the necessary condition of translation 1.A (acceptance) as sufficient condition.

B) Does not apply to the sufficient condition 2.B (Reasonably believed to be said in jest) that would void contract.

C) No conditional relation applicable

D) Confuses a necessary condition of 1.B (Was not reasonably believed to be said in jest) as a sufficient condition for a legit offer.

E) if not legit then not valid (2.A)

Conclusion: We must abandon the belief that the oversized head, long hind legs, and tiny forelimbs of the T-Rex developed to accommodate its great size and weight.

Why?

Premise: (Because) We discovered a specimen that had oversized head, long hind legs, and tiny forelimbs but was one-fifth the size and one-hundredth of the weight.

Assumption: What we observed from this specimen can be applied to what we believe about the T-Rex.

B target that assumption. If the specimen is fully developed then perhaps we can side with the challenger. If the specimen is not fully developed then we cannot apply what we observed to what we believe about the fully developed T-Rex. Its important we know what stage of development the specimen was at to determine whether our observations apply to the T-Rex.

Conclusion: Lucinda will probably live in Western Hall.

L‑m→W

Why?

Premise: (Because) Most residents of Western Hall are Engineering majors.

Lucinda is an engineering major.

W‑m→E

L→E

-----------------

L‑m→W

This is flawed because no conclusion can be sufficiently made. Most students in Western Hall are engineering majors but that does not mean most engineering majors are in in Western Hall.

A‑m→B

C→B

----------------

C‑m→A

AC E:

Conclusion: Our city will probably become a regional economic hub.

C‑m→H

Why?

Premise: (Because) most cities that are regional economic hubs contain major shopping malls.

Our city is constructing a major shopping mall.

H‑m→MSM

C→MSM

-------------------------

C‑m→H

A match:

A‑m→B

C→B

-------------------

C‑m→A

E negated: Even if a weather pattern with a natural cause has a seven-day cycle, it does not necessarily mean that the cause has a seven-day cycle

If E is negated, then the premise of the argument is null.

thank you!

Top tip: the degree of the conclusion will directly be equal the degree of the conclusion in the right answer.

All Candidates → Small-Business Owner

Most Small-Business Owner→ Competent Manager

Competent Manager→ Necessary Skills

C→ SBO ‑m→ CM → NS

----------------------------

C ‑m→ NS

"All" is before "Most" so no valid argument can be made.

"A" is a trap answer choice in that, it does not match the format and it's a valid argument.

Sales→ At least 1 year

Managament ‑m→ Sales

At least 1 year → Understand marketing.

M ‑m→ S→ 1 year → UM.

---------------------------------------------------------

M ‑m→ UM.

"B" says:

Menu → Fat-free

Fat-free ‑m→ sugar free → low calories

M→ FF‑m→ SF‑m → LC

------------------------------------------

M ‑m→ LC

"All" is before "Most" so no valid argument can be made.

Since the conclusion deals with probability, we know that this is inductive reasoning, and therefore cannot be drawn out using formal logic.

Conclusion: It seems probable that the invention of money occurred independently in more than one society.

Why?

Premise: (Because) it is universal but not rooted in innate ability.

SA: some societies have been isolated enough not to have been influenced by any other society.

Argument: Since some societies have been isolated enough not to have been influenced by any other society and money is universal but not rooted in innate ability, it seems probable that the invention of money occurred independently in more than one society.

Explanation: the SA is "eliminative" evidence (we strengthen the argument by eliminating reasons for doubting its validity). In other words, we are making it clear that conclusion is probable because it is possible. This is a purely inductive strategy.

All bankers are athletes.

B→A

None of the lawyers are bankers.

L→ /B

Remember, in (B→A) "A" is the superset" and "B" is the subset.

So, when it says (B→/L), all this tells us is that L has no overlap in subset B, but this doesn't tell us whether L's membership falls outside of the superset A.

At most we know that L is not a superset of A = not(L→A).

The negation of "all" is "some not"

L←s→/A or A←s→/L

8. E)"during the drilling of an oil well, drilling mud is continuously discharged into the sea." is not supported by either passage. We know Passage A does not touch on disposal at all so they only place it could be stated is in passage B. But passage B explicitly say: "drilling muds are normally released only during the drilling phase of the well's existence. (Line 31-32) and that "releases are controlled" (line 36-37).

So, there's a difference between a continuous release and a controlled one. A continuous release literally means one without interruption whereas a controlled release would imply intervals. So, Passage B does not support AC E.

These types of passages can be considered more difficult because the author does not offer an argument. Usually when the author offers an argument, their argument is the main point, and the purpose of the passage is to convey the author's argument. In this case, the author does not provide an argument, so this is a "presentation" passage. Instead of the main point being the author's argument, the main point is just the main takeaway. In other words, what did we learn from the passage. Therefore, the main point of the passage is that we learned that platypuses hunt prey using their bill. But since the author does not offer an argument, the purpose in a "presentation" passage is not to convey the "author's" argument. The purpose of a "presentation" passage is to convey the main takeaway. In other words, how did the author present the main takeaway. If we were to describe how the author presented the main takeaway, we would see that they do so by describing two recent studies. That is how we get 16 and 17 correct. We can also get 21 correct by recognizing that the author presents the main takeaway (MP) and supports it by describing the two studies that brought about the main takeaway (purpose).