Question 560466: A man is twice as old as his son. His son is twice as old as his sister. The total age is 84. What is the father's age? Found 2 solutions by stanbon, josmiceli:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! A man is twice as old as his son. His son is twice as old as his sister. The total age is 84. What is the father's age?
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Equations:
m = 2s
s = 2S
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m + s + S = 84
2s + s + (s/2) = 84
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(7/2)s = 84
(1/2)s = 12
s = 24 yrs (son's age)
m = 2s = 48 (man's age)
S = s/2 = 12 (sister's age)
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Cheers,
Stan H.
You can put this solution on YOUR website! Let = Son's age
Let = Sister's age
Let = Father's age
given:
(1)
(2)
(3)
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This is 3 equations and 3 unknowns, so it's solvable
(2)
Substitute (1) and (2) into (3)
(3)
and
and
The Father is 48, the Son is 24, and the Sister is 12
check:
(3)
(3)
(3)
OK
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