LSAT 107 – Section 1 – Question 10

LSAT 107 - Section 1 - Question 10

October 1999

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Question
QuickView		 Type Tags Answer
Choices		 Curve Question
Difficulty		 Psg/Game/S
Difficulty		 Explanation
PT107 S1 Q10
+LR
Resolve reconcile or explain +RRE
A
2%
158
B
3%
158
C
1%
158
D
84%
165
E
9%
159
135
146
157
 +Medium 147.515 +SubsectionMedium

The symptoms of hepatitis A appear no earlier than 60 days after a person has been infected. In a test of a hepatitis A vaccine, 50 people received the vaccine and 50 people received a harmless placebo. Although some people from each group eventually exhibited symptoms of hepatitis A, the vaccine as used in the test is completely effective in preventing infection with the hepatitis A virus.

"Surprising" Phenomenon
Why did people who received the hepatitis A vaccine exhibit symptoms of hepatitis A?

Objective
A hypothesis resolving this discrepancy must reveal new information about the group who received the vaccine. It should either indicate their infection with hepatitis A prior to inoculation or distinguish between the hepatitis A virus and the symptoms it causes.

A
The placebo did not produce any side effects that resembled any of the symptoms of hepatitis A.
This does not imply that the vaccine did produce such side effects. It refers to placebo recipients only, and does not address the discrepancy, which involves only vaccine recipients.
B
More members of the group that had received the placebo recognized their symptoms as symptoms of hepatitis A than did members of the group that had received the vaccine.
This is irrelevant information. There is no indication that participants self-reported their symptoms, so this difference in attribution between the groups would not have affected the study.
C
The people who received the placebo were in better overall physical condition than were the people who received the vaccine.
This does not explain why people who received the vaccine developed hepatitis A symptoms. The discrepancy is not between the two groups, but between the vaccine's complete effectiveness and the hepatitis A symptoms among the people who received it.
D
The vaccinated people who exhibited symptoms of hepatitis A were infected with the hepatitis A virus before being vaccinated.
This resolves the apparent paradox by explaining that vaccine recipients were infected prior to inoculation. It is consistent because the author gives no information about the vaccine's effect on patients already infected with hepatitis A.
E
Of the people who developed symptoms of hepatitis A, those who received the vaccine recovered more quickly, on average, than those who did not.
This does not explain how vaccine recipients developed symptoms in the first place. If the vaccine is completely effective, patients who received it should not have contracted hepatitis A.

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LSAT PrepTest 107 Explanations

Section 1 - Logical Reasoning

Section 2 - Reading Comprehension

Section 3 - Logical Reasoning

Section 4 - Logical Reasoning

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