Question 482229
Father present age= f
Son’s present age=s

the age of father is 3 years more than 3 times the age of his son.
So father’s age will be 
f=3s+3 ……………(1)
After 3 years the age of the father will be 10 years more than twice the age of the son.
f+3=2(s+3)+10……….(2)

Solve equation (2)
f+3=2(s+3)+10
f=2s+6+10-3
f=2s+13
3s+3=2s+13
3s-2s=13-3
s=10

Put the value of s in equation (1)
f=3s+3
f=3(10)+3
f=30+3
f=33

Father is 33 and son is 10 years old.