SOLUTION: A father is now twice as old as his son.if the sum of their ages ten years ago was 52, find their present ages.

Let x be the son's present age. Then the father's present age is 2x, according to the solution.


Since  "the sum of their ages ten years ago was 52", this sum is 52 + 2*10 = 72 years now.


Hence, x + 2x = 72, i.e. 3x = 72. Hence, x =  = 24.


Thus the son's present age is 24 years.


Then that of the father is 2*24 = 48 years.