Question 995160
A boy now one third as old as his father ,twelve years later he will be half as old as his father.then the present age of the boy is 
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Equations:
b = (1/3)f
b+12 = (1/2)(f+12)
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Substitute for "b" and solve for "f"::
(1/3)f + 12 = (1/2)(f+12)
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Multiply thru by 6 to get rid of the fractions::
2f + 72 = 3(f+12)
2f + 72 = 3f + 36
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f = 36 (father's age now)
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boy = (1/3)f = 12 yrs
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Cheers,
Stan H.
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