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Explanations

PT123.S3.Q17

SECTION 1 · rc

PASSAGE 1
Question 1 Question 2 Question 3 Question 4 Question 5 Question 6

PASSAGE 2
Question 7 Question 8 Question 9 Question 10 Question 11 Question 12 Question 13

PASSAGE 3
Question 14 Question 15 Question 16 Question 17 Question 18 Question 19 Question 20

PASSAGE 4
Question 21 Question 22 Question 23 Question 24 Question 25 Question 26

SECTION 2 · lr

Question 1 Question 2 Question 3 Question 4 Question 5 Question 6 Question 7 Question 8 Question 9 Question 10 Question 11 Question 12 Question 13 Question 14 Question 15 Question 16 Question 17 Question 18 Question 19 Question 20 Question 21 Question 22 Question 23 Question 24 Question 25

SECTION 3 · lr

Question 1 Question 2 Question 3 Question 4 Question 5 Question 6 Question 7 Question 8 Question 9 Question 10 Question 11 Question 12 Question 13 Question 14 Question 15 Question 16 Question 17 Question 18 Question 19 Question 20 Question 21 Question 22 Question 23 Question 24 Question 25

SECTION 4 · rc

PASSAGE 1
Question 1 Question 2 Question 3 Question 4 Question 5 Question 6 Question 7 Question 8

PASSAGE 2
Question 9 Question 10 Question 11 Question 12 Question 13 Question 14

PASSAGE 3
Question 15 Question 16 Question 17 Question 18 Question 19 Question 20 Question 21 Question 22

PASSAGE 4
Question 23 Question 24 Question 25 Question 26 Question 27

PrepTest 123 - Section 3 - Question 17

Question

Explanation

Analytics

Show analysis

When exercising the muscles in one's back, it is important, in order to maintain a healthy back, to exercise the muscles on opposite sides of the spine equally. After all, balanced muscle development is needed to maintain a healthy back, since the muscles on opposite sides of the spine must pull equally in opposing directions to keep the back in proper alignment and protect the spine.

Show answer

17.

Which one of the following is an assumption required by the argument?

Muscles on opposite sides of the spine that are equally well developed will be enough to keep the back in proper alignment.

This reverses the direction of a relationship in the argument. The argument establishes that balanced muscle development (or muscles pulling equally) is necessary for keeping the back in proper alignment. (A) claims that equally well-developed muscles would be sufficient for keeping the back in proper alignment. But the argument never needs that to be true. There could be other requirements for proper alignment beyond balanced muscle development. All the argument needs is that balanced development is one of the requirements, not that it's the only one.

Exercising the muscles on opposite sides of the spine unequally tends to lead to unbalanced muscle development.

Without this assumption, the conclusion wouldn't follow. The argument concludes that exercising muscles equally is important for a healthy back because balanced muscle development is needed. But this follows only if exercising unequally would actually undermine balanced development. If you could exercise the muscles unequally and still end up with balanced development, then the need for balanced development wouldn't be a reason to exercise equally. Why bother doing something if skipping it doesn't hurt?

The negation test confirms this. Negate (B): exercising unequally does not tend to lead to unbalanced development. If that's the case, then balanced development can happen even without equal exercise, and the whole reason for exercising equally evaporates. Since the negation of (B) undermines the argument, (B) is a necessary assumption.

Provided that one exercises the muscles on opposite sides of the spine equally, one will have a generally healthy back.

This reverses the direction of the main conclusion. The conclusion says that if you want a healthy back, exercising equally is important (i.e., it's necessary). (C) says that if you exercise equally, you will have a generally healthy back (i.e., it's sufficient). But the argument doesn't need equal exercise to guarantee a healthy back. It just needs equal exercise to be one of the things a healthy back requires. You might also need good posture, adequate rest, or any number of other things. Equal exercise could be necessary without being sufficient.

Don't be thrown off by the word "generally." It's not softening the claim into something weaker than sufficiency. It's saying you will have a back that is, in general, healthy. That's still a guarantee, and the argument doesn't need to make that guarantee.

If the muscles on opposite sides of the spine are exercised unequally, one's back will be irreparably damaged.

This is far stronger than what the argument requires. The argument assumes that exercising unequally tends to produce unbalanced development, which in turn is bad for back health. But it doesn't need to assume that exercising unequally causes irreparable damage. Maybe unbalanced development is something you can correct later by adjusting your exercise routine. The argument only needs equal exercise to be important for a healthy back, not that failing to do it causes permanent, unfixable harm.

One should exercise daily to ensure that the muscles on opposite sides of the spine keep the back in proper alignment.

The argument says nothing about how often to exercise. It claims that when you exercise your back muscles, you should exercise both sides equally. Maybe that's once a week, maybe that's once a month. The argument takes no position on frequency.

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Difficulty

Question

50% of people who answer get this correct

This is a difficult question.

CURVE

Score of students with a 50% chance of getting this right

25% 142

153

75% 164

Analysis

Question Stem Tags

Necessary assumption

Stems that ask us to identify a claim that, if NOT true, would entirely undermine the reasoning in the stimulus.

Stimulus Tags

Causal reasoning

Stimuli that feature the logic of causation (e.g. phenomenon-hypothesis, causal chain, experiments).

Link assumption

Arguments that feature an unjustified shift from one concept to another, which don't fit neatly into other common flaw categories (e.g. moving from premises about "houses" to a conclusion about "dwellings").

Answer Popularity

Popularity Avg. score

21%

151

50%

157

24%

148

145

140

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