Question 1035821
The 25 scores with a mean of 87 ==> the sum of the 25 scores is 2175.
The 21 of the 25 scores having a mean of 85 ==> the sum of the 21 scores is 1785.

==> Four of the scores had a sum of 2175 - 1785 = 390.
The mean of these four scores is 97.5.

The most a score can vary from 97.5 is 2.5 points. (Assuming that scoring more than 100 is not allowed.)

==> The lowest possible score from the fours scores is 95, while the highest possible is 100.

==> The largest possible difference between any two of the other four scores is 5.