Question 1149791
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Son     x

Father 3x


In 12 years


    3x+12 = 2*(x+12).


    3x+12 = 2x + 24

    3x-2x  = 24-12

    x = 12.


<U>Answer</U>.  The son is 12 years old.  The father is 3*12 = 36 years old.
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Solved.