arithmetic - thirteen years ago a father was three times as old as his son now the father is only twice as old as his son then the sum of the present ages of the son and the father is - skillgun

Solution: Let the present ages of the father and son be 2x and x respectively. Then, (2x-13) = 3(x-13) <==> x= 26.
.'. Required sum = 2x+x = 3x = 3*26 = 78 years.