Square of difference between two numbers is 9 while the sum of squares of those two numbers is 225. What is their product?

108

Let the 2 numbers be x and y. So, according to the question:

(x - y)² = 9 -------1st equation

x² + y² = 225 ----2nd equation

(x - y)² = 9 = x² + y² - 2xy = 9

Putting the values of 2nd equation in the above equation:

 x² + y² - 2xy = 9 

225 - 2xy = 9

2xy = 216

xy = 108

Thus, we can say that the product of the two numbers i.e. x and y is 108.