Answer: The rate at which the two boys are separating is 14.4 mph.
Explanation: The rate at which the two boys are separating can be found using the Pythagorean theorem.
Let's call the rate at which they are separating "R".
Using the Pythagorean theorem, we have:
R^2 = (12)^2 + (8)^2
Taking the square root of both sides:
R = √(12^2 + 8^2) = √(144 + 64) = √208 = 14.4 mph
So the rate at which the two boys are separating is 14.4 mph.