When i am as old as my father is now, i will be five times as old as my son is now. but then, my son will be eight years older than i am now. the combined ages of my father and myself are 100 years. how old is my son?

My son is 13 years old now.

Explanation

Suppose, my age , my father's age and my son's age

When I am as old as my father is now that means after years, I will be 5 times as old as my son is now. So, the equation is.....

And then means after years, my son will be 8 years older than I am now. So.....

Substituting equation (1) into equation (2), we will get.....

The combined ages of my father and myself are 100 years. So.....

Now substituting and into equation (4), we will get.....

So, my son's age is 13 years now.

step-by-step explanation: