Question

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?

Answer 1

the son will be 8 years only

Answer 2

Answer:

Explanation:

let m = my age now: let s = son's age: let f = father's age: let d = difference between my age and father's age (f - m):

From the statement "When I am as old as my father is now, I shall be five times as old as my son is now."

we can say: (m + d) = 5s = f: or :d = 5s – m :" By then, my son will be eight years older than I am now."s + d = m + 8.replace d with (5s-m).s + 5s - m = m + 8.6s - 2m = 8:" The combined ages of my father and myself are 100 years."f + m = 100.Replace f with 5s.5s + m = 100:How old is my son?multiply the above equation by 2 and add to; 6s - 2m = 8:10s + 2m = 200:6s - 2m = 8.By eliminating  m:16s = 208: s = 208%2F16: s = 13 yrs is my son's age.

Answer: my son is 13 year old.