Q. If 4 ≤ x ≤ 8 and 2 ≤ y ≤ 7, then what is the ratio of maximum value of (x + y) to minimum value of (x – y)?

Explanation : 

1. We are given the ranges
4 ≤ x ≤ 8
2 ≤ y ≤ 7

2. Find the maximum of (x + y).
• x + y is largest when x and y are as large as possible
• Take x = 8 and y = 7
⇒ max (x + y) = 8 + 7 = 15

3. Find the minimum of (x − y).
• x − y is smallest when x is as small as possible and y is as large as possible
• Take x = 4 and y = 7
⇒ min (x − y) = 4 − 7 = −3

4. Compute the ratio:
(maximum of x + y) / (minimum of x − y)
= 15 ÷ (−3)
= −5

None of the given positive options (6, 15/2, etc.) equals −5, so the correct choice is “None of the above.”