If the sum and diference of two numbers are 20 and 8 respectively, then the difference of their squares is :

120
140
160
180

Correct Answer: 160

Explanation:

Let the numbers be x and y. Then, x + y = 20 and x - y = 8.

x^2 - y^2 = (x + y) (x - y) = 20 x 8 = 160.

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