Question 722602
let f = father's age
let s = son's age
:
The sum of age of father and son is 75.
f + s = 75
the difference in their ages
d = f - s
:
If the father and his son both live until the son becomes as old as his father is now, the sum of the age will be 107.
:
(f + d) + (s + d) = 107
f + s + 2d = 107
we know that f + s = 75, from the 1st statement
75 + 2d = 107
2d = 107 - 75
2d = 32
d = 16 yrs is the their age difference (a young father)
;
f = s + 16
:
f + s = 75
(s+16) + s = 75
2s = 75 - 16
2s = 59
s = 59/2
s = 29.5 yrs is the son's age
then
29.5+16 = 45.5 yrs is father's age
:
:
See if this works: 
29.5 + 45.5 = 75
and
(29.5+16) + (45.5+16) = 
45.5 + 61.5 = 107