SOLUTION: A father is three times as old as his son. in 12 years time, he will be twice as old as his son . find the present age of the father and the son

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: A father is three times as old as his son. in 12 years time, he will be twice as old as his son . find the present age of the father and the son       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 762825: A father is three times as old as his son. in 12 years time, he will be twice as old as his son . find the present age of the father and the son
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +f+ = father's age now
Let +s+ = son's age now
given:
(1) +f+=+3s+
(2) +f+%2B+12+=+2%2A%28+s+%2B+12+%29+
-------------------------
(2) +f+%2B+12+=+2s+%2B+24+
(2) +f+-+2s+=+12+
Substitute (1) into this
(2) +3s+-+2s+=+12+
(2) +s+=+12+
and, since
(1) +f+=+3s+
(1) +f+=+3%2A12+
(1) +f+=+36+
The son is 12 and the father is 36
check:
(2) +f+%2B+12+=+2%2A%28+s+%2B+12+%29+
(2) +36+%2B+12+=+2%2A%28+12+%2B+12+%29+
(2) +48+=+2%2A24+
(2) +48+=+48+
OK