Answer:
The maximum value is 25.
Explanation:
We are given the set of numbers:

We wish to maximize x/y where both x and y are chosen from the given set.
To maximize the quotient, we must select x as the greatest number from the set and y as the smallest number from the set.
Testing the fractions we find:

Thus, the smallest number is 2/5
Select x=10, y=2/5
Now calculate the quotient:

The maximum value is 25.