Let the present of father be x years.
So, present age of his son = 50-x years.
Now, According to question,
put x-40=0 and x-10=0
x=40 , x=10
Now, rejecting x=10 because age of father can't be less than his son, we get
Hence, Present age of father = 40 years.
Present age of his son = 50-10=40 years.Ans.
let the present age of father is x
the son age is 50-x
father age =40
son age 50-40=10
= 800 (110)1/2