Question 424031: Frank is two thirds as a Adam. In seven years, frank will be three fourths as old as adam.how old are they now ? Found 2 solutions by stanbon, josmiceli:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Frank is two thirds as a Adam. In seven years, frank will be three fourths as old as adam.how old are they now ?
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Equations:
f = (2/3)a
(f+7) = (3/4)(a+7)
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Substitute for "f" and solve for "a":
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((2/3)a + 7) = (3/4)a + (21/4)
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(2/3)a - (3/4)a = (21/4)-7
(-1/12)a = -7/4
a = 21 yrs old (Adam's age now)
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Solve for "f":
f = (2/3)a
f = (2/3)21
f = 14 yrs old (Frank's age now)
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Cheers,
Stan H.
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You can put this solution on YOUR website! Let = Adam's age now
Let = Frank's age now
given:
(1)
(2)
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(2)
(2)
(2)
Substitute (1) in (2)
(2)
(2)
(2)
and
(1)
(1)
Adam is 21 now and Frank is 14 now
check:
(2)
(2)
(2)
(2)
OK
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