Respuesta :
Let Robert's age is 'x'
Robert's Father's age is four times as old as Robert = 4x
In five years time, Robert's age is = x + 5
and Robert's Father's age is = 4x + 5
In five years time:
Robert's Father's age = 3 × Robert's age
4x + 5 = 3 (x+5)
4x + 5 = 3x + 15
4x - 3x = 15 - 5
x = 5
Robert's present age = 5
Robert's Father's age = 4 × 5 = 20
Robert's Father's age is four times as old as Robert = 4x
In five years time, Robert's age is = x + 5
and Robert's Father's age is = 4x + 5
In five years time:
Robert's Father's age = 3 × Robert's age
4x + 5 = 3 (x+5)
4x + 5 = 3x + 15
4x - 3x = 15 - 5
x = 5
Robert's present age = 5
Robert's Father's age = 4 × 5 = 20
Answer:
Robert= x
Robert's Father= 4x
After 5 years,
Robert= x+5
Robert's Father= 3(x + 5)
4x+5= 3(x+5)
4x+5= 3x+15
4x-3x=15-5
x=5
Therfore,
Robert= 5
Robert's Father= 5x4= 20