Question 1200734
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x for Cal, 3x for Jon, and (x+12) for Ron.


Write equation for their total age now, which is 81 - 3*8 = 57

    x + 3x + (x+12) = 57


Simplify and find x

    5x = 57 - 12 = 45

    x            = 45/5 = 9.


<U>ANSWER</U>.  Cal is 9 years old;  Jon is 3*9 = 27 years old; Ron is 9+12 = 21 years old.
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Solved.