Is the following situation possible? If so, determine their present ages.

Let the age of one friend be x years.

Age of the other friend will be (20 − x) years.

4 years ago,

 age of 1^st friend = (x − 4) years

And, age of 2^nd friend = (20 − x − 4) = (16 − x) years

Given that,

(x − 4) (16 − x) = 48

= 16x − 64 − x² + 4x = 48

= x² − 20x + 112 = 0

Comparing this equation with ax² + bx + c = 0, we obtain

 a = 1, b = −20, c = 112

Discriminant = b² − 4ac = (− 20)² − 4 (1) (112) = 400 − 448 = −48

As b² − 4ac < 0,

Therefore, no real root is possible for this equation and hence, this situation is not possible.