Data Sufficiency

How many questions did Joey attempt in a math test having 25 questions?

A) Joey scored 16 marks.
B) For every correct answer, Joey got 1 mark while for every incorrect answer, Joey lost 0.25 marks.

The OA is E.

Please, can any expert explain this DS question for me? I have many difficulties to understand why that is the correct answer. Thanks.

swerve wrote:How many questions did Joey attempt in a math test having 25 questions?

A) Joey scored 16 marks.
B) For every correct answer, Joey got 1 mark while for every incorrect answer, Joey lost 0.25 marks.

The OA is E.

Please, can any expert explain this DS question for me? I have many difficulties to understand why that is the correct answer. Thanks.

This question is problematic - in the stem, it would have to be made clear that test-takers would receive an unspecified number of points for correct answers and incur an unspecified penalty for incorrect answers. (And presumably, questions not attempted would have no impact on the overall score or some other unspecified penalty.)

If we assume that questions not attempted have no impact on the overall score, we can see that even together, there would not be enough information to determine how many questions Joey attempted. It's possible that Joey had 16 correct answers and left the last nine blank, or that he had 17 correct answers, answered 4 incorrectly, and left 4 blank, etc, so the answer would have to be E That said, this source strikes me as dubious.