SOLUTION: a father is thirty times older than his son. However 18 years later he will only thrice as old as the son. What is the fathers present age

This is a weird problem.  If the son were only 2, the father would be 60.
60-year old men normally do not have children that young, so to be true to
life, the son can only be a baby.  Ages of babies are given in months, so 
let's work the problem in months.

Son's age in months = x
Father's age in months = 30x
Son's age in 18 years = Son's age in 18*12 or 216 months = x+216
Father's age in 18 years = Father's age in 216 months = 30x+216

30x + 216 = 3(x + 216)
30x + 216 = 3x + 648
      27x = 432
        x = 16

So the child is a small tot 16 months old, or 1 year and 4 months old.

Answer:  The father is 30*16 or 480 months or 480/12 = 40 years old

Checking:

40 is 480 months old, which is 30 times 16 months.

In 216 months, the child will be 232 months old, or 19 years and 4 months
and the father will be 480+216 or 696 months or 58 years old.

It's right but the problem is weird.

Edwin