Question 754898: the sum of the ages of the parents and the three children is decades over a century. The father is twice as old as the eldest child. When the eldest child was born, the sum of the parents age is 54. When the youngest child was born, the sum of the parents age was 54. In 38 years, the sum of the parents ages will be equal to the sum of the childrens ages. How old is the second child?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! the sum of the ages of the parents and the three children is decades over a century.
The father is twice as old as the eldest child.
When the eldest child was born, the sum of the parents age is 54.
When the youngest child was born, the sum of the parents age was 54.
In 38 years, the sum of the parents ages will be equal to the sum of the childrens ages.
How old is the second child?
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f is father; m is mother; e is eldest; y is youngest; k is middle child
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Equations:
f = 2e
e = (f+m)-54
y = (f+m)-54
(f+m)+38 = e+38 + y+38 + k +38
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Rearrange to solve for "k"
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Substituting 2e for "f":
e = 2e+m-54
y = 2e+m-54
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Using: f+m+38 = e+38 + y+38 + k +38 solve for "k":
2e + m + 38 = e+38 + (2e+m-54 + 38) + k + 38
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2e+m+38 = 3e + m + k + 60
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k = -e - 22
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Check that out. There may be some mistake(s) in it.
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Cheers,
Stan H.
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