anik1989 wrote:

A test is scored out of 100 and the scores are divided into five quintile groups. Students are not told their scores,

but only their quintile group.

Quanti ty A

The scores of two students in the bottom quintile

group, chosen at random and added together

Quanti ty B

The score of a student in the top

quintile group, chosen at random

In this problem, we are NOT specifically told the scores of each quintile groups.

Then we can think that for A the 2 students' grades woould be 50 and 51 whose total would be 101

or the 2 students' grades woould be 30 and 31 whose total would be 61.

Then we can assume that the scores of student in the top

quintile group is 100 or 80.

In this way, we cann know that the answer is D.