SOLUTION: fred is 3 years more than two and one-half times his sister's age. of fred is 18, how old is his sister?

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Question 903539: fred is 3 years more than two and one-half times his sister's age. of fred is 18, how old is his sister?
Found 2 solutions by Alan3354, stanbon:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Subtract 3 from Fred's age, that's 2.5 times his sister's age.

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
fred is 3 years more than two and one-half times his sister's age. of fred is 18, how old is his sister?
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Equation:
f = (2.5)s + 3
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Solve for "s" if f = 18::
18 = (2.5)s + 3
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2.5s = 15
s = 15/2.5
s = 6 years (Sister's age now)
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Cheers,
Stan H.
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