Answer:
age of son= X
Father's age =3x
After 10 years , father's age= 3x +10
Son's age = X+10
Operations:
3x + 10 =2(x + 10 )
3x + 10 = 2x + 20
X= 10
Therefore, present age of son= 10 years
Father's present age = 30 years
After 10 years son will be 20 years and the father 40 yes which is double