Question 1191555:   
In three years' time, a father will be three times as old as his son. If the ratio of their ages is 2:7, find their present age. 
 Answer by ikleyn(52903)      (Show Source): 
You can  put this solution on YOUR website! . 
In three years' time, a father will be three times as old as his son.  
If the ratio of their ages is 2:7, find their present age. 
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Their current ages are 2x (the son) and 7x (the father), where x is the common measure,
now unknown.
To find this unknown, we have this equation ("three years later")
    7x + 3 = 3*(2x+3).
Simplify and find x
    7x + 3 = 6x + 9
    7x - 6x = 9 - 3
       x    =   6
ANSWER.  Their current ages are 2*6 = 12 years (the son)  and 7*6 = 42 years (the father).
 
Solved.
 
 
 
 
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