Question 783331
At the time I was born, I forgot the year, my only sister Nithya , happened to be just one quarter the age of my mother and she is now one third the age of our father’
Let s = Sunny's age
Let n = Nithya' age
Let m = Mom's age
Let f = Dad's age
:
When I was born:
my only sister Nithya , happened to be just one quarter the age of my mother
n - s = .25(m - s)
n - s = .25m - .25s
n =  .25m - .25s + s  
n = .25m + .75s
and she is now one third the age of our father’
n = .33f
n = n, therefore
.33f = .25m + .75s
I am just a quarter of my mother’s present age
s = .25m
Replace .25m with s
.33f = s + .75s
.33f = 1.75s
Multiply both sides by 3
f = 5.25s
 and in four years time I shall be a quarter the age of my father.
(s+4) = .25(f+4)
s + 4 = .25f + 1
s = .25f + 1 - 4
s = .25f - 3
replace f with 5.25s
s = .25(5.25s) - 3
s = 1.3125s - 3
3 = 1.3125s - s
3 = .3125s
s = 3/.3125
s = 9.6 yrs is Sunny's present age
;
I was expecting an integer solution (hoping!) but this seems to check out
I got
n = 16.8
m = 38.4
f = 50.4