The father is 4 times more than his son's age. After 10 years, he would be 25/9 times that of his son's age. After another 10 years, how many times would he be of his son's age?

Let the son's present age be s, making the father's present age 5s since he is 4 times older than his son. After 10 years, the father's age of 5s plus 10 equals 25/9 times the son's age of s plus 10, so 45s plus 90 equals 25s plus 250. Solving for s gives a value of 8, meaning the present ages are 40 for the father and 8 for the son. After another 10 years, 20 years will have passed since the start, making the father 60 years old and the son 28 years old. The ratio of 60 to 28 simplifies to 15/7, so the father will be 15/7 times his son's age.

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