aeros232 wrote:

97 students take part in a test and the median score is 85. Which of the following descriptions must be correct?

I. At least 49 students’ score are equal to or more than 85.

II. At least 49 students’ score are less than 85.

III. At most 49 students’ score are equal to or more than 85.

A. I

B. II

C. III

D. I & II

E. I & III

Need help since I don't agree with the answ.

You are right, the correct answer is not E.

If we order the scores increasingly, then on the 49th place we have the score of 85. There must be 48 scores (those on the right of the 85 score) greater or equal to 85. So, I is necessarily correct.

The scores on the left of the 49th place, all have to be equal or less than 85. Since we can have the extreme case of all the scores 85, neither II, nor III is correct. The question asks for descriptions that "

must be correct".

Answer A.

_________________

PhD in Applied Mathematics

Love GMAT Quant questions and running.