Akela
Any student who is not required to hand in written homework based on the reading assignments in a course will not complete all of the reading assignments. Even highly motivated students will neglect their reading assignments if they are not required to hand in written homework. Therefore, if the students in a course are given several reading assignments and no written assignments, no student in that course will receive a high grade for the course.
The conclusion of the argument follows logically if which one of the following is assumed?
(A) No student who completes anything less than all of the reading assignments for a course will earn a high grade for that course.
(B) Any student who completes all of the reading and written assignments for a course will earn a high grade in that course.
(C) All highly motivated students who complete all of the reading assignments for a course will receive high grades for that course.
(D) If highly motivated students are required to hand in written homework on their reading assignments, then they will complete all of their reading assignments.
(E) Some highly motivated students will earn high grades in a course if they are required to hand in written homework on their reading assignments.
The argument centers around finding the supporter assumption as clearly there is a jump from failing to complete reading assignments to obtaining a high grade. First two sentences are premise whereas the last sentence is the conclusion. Observe that the second sentence does not convey any new information.
First statement already says that 'For all students, If no written homework, then reading assignments will be incomplete'
Second statement says that 'For highly motivated students, If no written homework, then reading assignments will be incomplete'
Finally, conclusion says 'If no written homework, then no high grade'
From the first two statements we know that If no written homework then reading assignments will be incomplete. Hence for the author to logically draw the conclusion he or she needs to assume that
If reading assignments are not completed, then no high grade or in other words For a high grade, completing reading assignments is
NECESSARY.
Choice (A) is another way of saying that completing reading assignments is NECESSARY
Choice (B) says that completing reading assignments is SUFFICIENT to earn a high grade. We cannot say this as there could be many criteria that need to have been met in order to earn a high grade. For example, attendance must be 70 percent etc
Choice (C) again makes reading a SUFFICIENT condition
Choice (D) does not follow from the argument. Also, since it does not talk about high grades, it does not link the premises to the conclusion.
Choice (E) again makes reading a SUFFICIENT condition.