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Explanations

PT13.S2.Q10

SECTION 1 · 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 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 Question 26

SECTION 3 · 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

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 Question 27

SECTION 4 · lr

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PrepTest 13 - Section 2 - Question 10

Question

Explanation

Analytics

Show analysis

Every political philosopher of the early twentieth century who was either a socialist or a communist was influenced by Rosa Luxemburg. ██ ███ ███ ███ ██████████ ██ ████ █████████ █████████ █ ████████████ ██████

Disjunctions

The core of this argument is a straightforward conditional chain, complicated slightly by adding an “or” statement in the first term. It’s also a great place to practice kicking concepts up into the domain. Here are translations of the premises in English and formal logic, along with the valid inference we get by linking the premises:

English
(Domain: early 1900s political philosophers)
If you were a socialist or communist, you were influenced by Rosa.
If you were influenced by Rosa, you didn’t advocate totalitarianism.
________
If you were a socialist or communist, you didn’t advocate totalitarianism.

Logic
(Domain: early 1900s political philosophers)
Socialist or Communist → Rosa
Rosa → /Totalitarian
________
Socialist or Communist → /Totalitarian

When a MBT stimulus yields clear formal logic inferences, you can anticipate with some confidence that the correct answer choice will express one of those inferences.

Analysis by MichaelWright

Show answer

10.

If the statements above are █████ █████ ███ ██ ███ █████████ ████ ██ ███ █████ ██ ████ ████ ██ █████

No early-twentieth-century socialist █████████ ███████████ █████████ █ ████████████ ██████

This expresses one of the valid inferences we can draw from the premises in the stimulus. It’s important to note that the “or” statement (socialist or communist) means satisfying either one (or both) of those conditions suffices to say that person was influenced by Rosa.

If you’re a socialist you’re [either a socialist or a communist], which means you were influenced by Rosa, which means you didn’t advocate a totalitarian state.

Socialist → /Totalitarian

Every early-twentieth-century political ███████████ ███ ███ ███ ████████ █ ████████████ █████ ███ ██████████ ██ ████ ██████████

(B) is the sufficiency-necessity confused version of the stimulus’ second sentence – it’s backward, and that’s not a valid move. There could have been other philosophers (perhaps some libertarians, for instance) who also didn’t advocate a totalitarian state even though they weren’t influenced by Rosa.

Rosa Luxemburg was ███ ████ ██████ ██ █████████ █████ ███████████████████████ █████████ ███████████ ███ ███ ██████ █████████ ██ ██████████

(C) commits a fallacy I like to call “why not both?” Just because these philosophers were influenced by Rosa doesn’t mean they can’t also be influenced by someone else. There’s no rule saying philosophers can only be influenced by one person at a time.

Every early-twentieth-century political ███████████ ███ ███ ██████████ ██ ████ █████████ ███ ███ ███ █ █████████ ███ █ ██████████

(D) demonstrates some solid logical reasoning, it just starts with the sufficiency-necessity confused version – a backward version – of the stimulus’ first sentence, which is no good. Here’s how (D) is supposed to work, starting with the backward premise:

English
If you were influenced by Rosa, you were a socialist or communist.

Logic
Rosa → Socialist or Communist

According to (D), people influenced by Rosa must be socialist or communist. If we then learn they aren’t a socialist, we can conclude they must be a communist.

Those inferences are great – it’s just that the opening premise isn’t supported by the stimulus.

Every early-twentieth-century political ███████████ ███ ███ ███ ████████ █ ████████████ █████ ███ ██████ █████████ ██ ██████████

(E) is the sufficiency-necessity confused version of the valid inference we can draw from the premises – it’s backward. See the analysis section for more detail.

Difficulty

Question

81% of people who answer get this correct

This is a moderately difficult question.

CURVE

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

25% 140

151

75% 162

Analysis

Question Stem Tags

Must be true

Stems that ask which answer choice "must be true." Related to Inference and MSS, but correct answers require 100% support with no assumptions of any kind. Learn more.

Stimulus Tags

Conditional reasoning

Stimuli that feature conditional and set logic (e.g. A → B, A is true, therefore B is true). Learn more.

Answer Popularity

Popularity Avg. score

81%

169

162

161

162

161

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