SOLUTION: Suasan is three times as old as nancy, and Carrie is 5 years younger than Susan. Three years ago the sum of their ages was 56. What was nancy age four years ago?

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Question 902666: Suasan is three times as old as nancy, and Carrie is 5 years younger than Susan. Three years ago the sum of their ages was 56. What was nancy age four years ago?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Susan is three times as old as nancy, and Carrie is 5 years younger than Susan. Three years ago the sum of their ages was 56. What was nancy age four years ago?
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Equations:
s = 3n
c = s-5
s-3 + n-3 + c-3 = 56
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s + n + c = 65
Substitute for n and for c; solve for "s"::
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s + (s/3) + s-5 = 65
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s + (1/3)s + s = 65
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(7/3)s = 65
s = (3/7)65
s = 27.86 years (Susan's age now)
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n = (1/3)s = (1/3)27.86 = 9.29 years (Nancy's age now)
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c = s-5 = 22.86 years (Susan's age now)
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Nancy's age 4 years ago:: n-4 = 5.29 years
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Cheers,
Stan H.
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