PT106.S1.Q12 > Analytics

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 Question 26

SECTION 2 · lr

SECTION 3 · lr

SECTION 4 · rc

PASSAGE 1

Question 1 Question 2 Question 3 Question 4 Question 5

PASSAGE 2

Question 6 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 Question 21

PASSAGE 4

Question 22 Question 23 Question 24 Question 25 Question 26

Dooney County isn’t flat. How do we know? The author sets up a conditional argument with two key premises:

(1) If farmland is flat, then farmers don’t build terraces to prevent erosion on that land.

(2) In Dooney County, there are terraces on farmland (at least, so the author hears).

The author tries to use premise (2) to trigger the contrapositive of premise (1). But he relies on several assumptions to make that contrapositive work:

- What he’s heard about terraces on Dooney County’s farms is true. (Otherwise, there’s no reason to think there are any terraces.)

- Some terraces in Dooney County were built to prevent erosion. (If they were for another purpose, they tell us nothing about whether the land is flat.)

- Some terraces in Dooney County were built by farmers. (If other people built them all, we can’t infer anything about the land.)

It’s the presence of terraces, not the specifics of erosion, that the argument depends on. Even if other causes of erosion exist, we know that on flat land, water-caused erosion isn’t a problem, and so any time farmland is flat, farmers won’t build terraces to prevent erosion.

This must be true for the author to infer that Dooney County is not flat. If (B) weren’t true—if there are no terraces that were specifically built to prevent soil erosion—then whatever terraces are there tell us nothing about whether the land is flat.

Whether the terraces happen to prevent erosion is irrelevant. What matters is what the terraces were built to do. For the argument to work, the terraces must have been specifically built (by farmers) to prevent erosion. Otherwise, the presence of terraces means nothing.

It’s the presence of terraces, not the specifics of erosion, that the argument depends on. Even if erosion occurs on flat land, we know that water-caused erosion isn’t a problem, and so any time farmland is flat, farmers won’t build terraces to prevent erosion.

Too strong. The argument only requires that at least some terraces in Dooney County are on farmland (because it’s the presence of farmland terraces that can help tell us whether the land is flat). Whether or not terraces also exist on other kinds of land is irrelevant.

Question

76% 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% 132

149

75% 165

Question Stem Tags

Necessary assumption

Stimulus Tags

Conditional reasoning

Popularity Avg. score

10%

166

76%

168

165

157

164

You don't have any history with this question.. yet!

PrepTest 106 - Section 1 - Question 12

Difficulty

Analysis

Answer Popularity

Question history

Confirm action