SOLUTION: A girl is now one-fourth as old as her father, and in seven years she will be one-half as old as her father was twelve years ago. Find their present ages. The father's present a

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Question 581203: A girl is now one-fourth as old as her father, and in seven years she will be one-half as old as her father was twelve years ago. Find their present ages.
The father's present age is .
The daughter's present age is .

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
let d = daughter's present age
let f = father's present age
:
write an equation for each statement:
:
"A girl is now one-fourth as old as her father,
d = 1%2F4f
or
f = 4d
:
"in seven years she will be one-half as old as her father was twelve years ago."
d + 7 = 1%2F2(f-12)
multiply both sides by 2
2(d+7) = f - 12
2d + 14 = f - 12
2d = f - 12 - 14
2d = f - 26
From the 1st statement, replace f with 4d
2d = 4d - 26
26 = 4d - 2d
26 = 2d
d = 13 yrs is daughter's age
then
4(13) = 52 yrs is father's present age
;
;
Check this in the statement:
"in seven years she will be one-half as old as her father was twelve years ago."
13 + 7 = 1%2F2(52-12)
20 = 1%2F2(40)