SOLUTION: When I am as old as my father is now, I will five times as old as my son is now. By then, my son will be eight years older than I am now. The sum of my father's age and my age is 1

Question 208974: When I am as old as my father is now, I will five times as old as my son is now. By then, my son will be eight years older than I am now. The sum of my father's age and my age is 100 years. How much older am I than my son?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
When I am as old as my father is now, I will five times as old as my son is now. By then, my son will be eight years older than I am now. The sum of my father's age and my age is 100 years. How much older am I than my son?
:
m = my age now
f = father's age now
s = son's age now
d = f - m; (me and dad's age difference)
:
"When I am as old as my father is now, I will five times as old as my son is now."
father now is 5 times son now
f = 5s
we can substitute 5s for f and we have difference of
d = 5s - m
:
"By then, my son will be eight years older than I am now."
(s + d) = m + 8
Substitute (5s-m) for d
s + (5s - m) = m + 8
6s - m - m = 8
6s - 2m = 8
:
"The sum of my father's age and my age is 100 years."
f + m = 100
Substitute 5s for f
5s + m = 100
Multiply this equation by 2 and add to eq: 6s - 2m = 8
10s + 2m = 200
6s - 2m = 8
----------------adding eliminates m, find s
16s = 208
s =
s = 13 yrs is son's present age
then
5(13) = 65 yrs is father's present age
:
It's easy to find my age
65 + m = 100
m = 35 yrs is my age
;
;
Check solutions in the statement: (d = 65 - 35 = 30 yrs difference)
"By then, my son will be eight years older than I am now."
13 + 30 = 35 + 8
:
Dad: 65, me 35, son 13
RELATED QUESTIONS
When I am as old as my father is now, I shall be five times as old as my son is now. By... (answered by ankor@dixie-net.com)

When I am as old as my father is now, I shall be five times as old as my son is now. By... (answered by rapaljer)

When a man is asked how old is he, he replied "I am four times as old as my eldest son... (answered by greenestamps,ikleyn)

i am 3 times old as my son. 5 years later i will be 2 and half times older than my... (answered by lwsshak3)

I am currently 5 times as my son in 6 years i will be three times as old as he will be... (answered by lwsshak3)

Father is five times as old as his son now. In six years,he will be three times as old as (answered by macston)

I am 23 years older than my son Arnez Jr who is 15. How old will I be when I am 3 times... (answered by Alan3354)

In 2 years I will be 5 times as old as my son and half as old as my father. My father... (answered by richwmiller)

In 2 years I will be 5 times as old as my son and half as old as my father. My father... (answered by mananth)