Critical Reasoning

A teacher separated his students into three groups: successful, borderline successful, and unsuccessful. Sixty percent of the teacher’s students were placed in the first category, fifteen percent were placed in the second category, and twenty-five percent were placed in the third category; the teacher concluded that most of his students were successful.

In order for the teacher’s conclusion to be logically correct, it is necessary to assume that


a student who is not in the top sixty percent of the class is not successful

students in this teacher’s class are more likely to be successful than are most other students

students in classes in which only the top thirty percent are categorized as successful are more likely to succeed in a non-academic setting than are students in this teacher’s class

students are more likely to be successful than unsuccessful

it is possible to categorize students accurately as being successful, borderline successful, or unsuccessful

I think option A & D are relavent. So confused abt 2. But in the end i think A is better than D.
OA pls

I think the correct answer is E. In order for the conclusion to be correct, we need to assume that the teacher's system for categorizing students is reasonable.

A is not a necessary assumption because even if a student who was not in the top sixty percent was successful it doesn't effect the conclusion that most (ie. >50%) were successful.

I don't see why D would be a necessary assumption either.

E for me.

One more vote for E

Negate E)

it is NOT possible to categorize students accurately as being successful, borderline successful, or unsuccessful.

The conclusion falls apart- >If it is not possible to categorzie the sudents as successful, borderline successful, or unsuccessful then the teacher cannot conclude that most of her students are successful

I agree with Cramya, if you can't categorize the students. The conclusion fails.

IMO E

I feel it is E