SOLUTION: A father is three times as old as his son. After fifteen years, the father will be twice as old as his son's age at that time. Therefore, the father's current age is? 1. 4 2. 8

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: A father is three times as old as his son. After fifteen years, the father will be twice as old as his son's age at that time. Therefore, the father's current age is? 1. 4 2. 8      Log On

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Question 194778: A father is three times as old as his son. After fifteen years, the father will be twice as old as his son's age at that time. Therefore, the father's current age is?
1. 4
2. 8
3. 16
4. 32
5. 64

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let f= the Father's age now
Let s= the Son's age now
f+%2B+15= the Father's age in 15 years
s+%2B+15= the Son's age in 15 years
given:
(1) f+=+3s
(2) f+%2B+15+=+2%2A%28s+%2B+15%29
Substitute (1) in (2)
3s+%2B+15+=+2%2A%28s+%2B+15%29
3s+%2B+15+=+2s+%2B+30
s+=+30+-+15
s+=+15
And
(1) f+=+3s
f+=+3%2A15
f+=+45
The Father is 45 and the Son is 15
check:
(2) f+%2B+15+=+2%2A%28s+%2B+15%29
45+%2B+15+=+2%2A%2815+%2B+15%29
60+=+60
OK
It's not one of the choices,
so something isn't right.