What is the minimum product of two numbers whose difference is 60? what are the numbers?

The minimum product would be a negative number with the maximum absolute value.
To get a negative number, the numbers must be opposite in sign.
The maximum absolute value would be attained when the two numbers have the same absolute value.

From the above, the minimum product would be -30 * 30 = -900.
(note 30-(-30)=60)