Suppose to create simultaneous equations and solve

Son’s age: x
Father’s age: y

Twice the son’s age is added to the father’s age ==> “new father’s age” = y + 2x

This means that the total age of the son and “father” = x + (y + 2x) = 3x + y

So, 3x + y = 70

But if the father’s age is added to the son’s age ==> “new son’s age” = y + x

This means that the total age of the “son” and father = (y + x) + y = x + 2y

So, x + 2y = 95

You will get x = 9, y = 43.

Son’s age is 9, father’s age is 43.

I admit that this question is a bad question because I misunderstood it at first - I know how you interpreted the question to obtain a negative answer.

Quite a bad question in my opinion - the objective of a particular maths question is not supposed to be testing the students on their English skills.