Square of difference between two numbers is 9 while the sum of squares of those two numbers is 225. What is their product?
Answer & explanation
Correct answer: option 2
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.