SOLUTION: Charles is one third as old as his father. In six years, Charles will be three sevenths as old as his father. If charles is less than 18 years old, how old is charles' father?

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Question 1096175: Charles is one third as old as his father. In six years, Charles will be three sevenths as old as his father. If charles is less than 18 years old, how old is charles' father?
Found 2 solutions by ankor@dixie-net.com, MathTherapy:
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Charles is one third as old as his father.
c = 1%2F3f
or
f = 3c
In six years, Charles will be three sevenths as old as his father.
c + 6 = 3%2F7(f + 6)
get rid of that annoying fraction, multiply both sides by 7
7(c + 6) = 3(f + 6)
7c + 42 = 3f + 18
7c = 3f + 18 - 42
7c = 3f - 24
Replace f with 3c
7c = 3(3c) - 24
7c = 9c - 24
24 = 9c - 7c
24 = 2c
c = 24/2
c = 12
:
If charles is less than 18 years old, how old is charles' father
f = 3(12)
f = 36 yrs is the age of the father
:
:
:
Check this
12 + 6 = 3%2F7(36+6)
18 = 3%2F7*42

Answer by MathTherapy(10549) About Me  (Show Source):
You can put this solution on YOUR website!
Charles is one third as old as his father. In six years, Charles will be three sevenths as old as his father. If charles is less than 18 years old, how old is charles' father?
The statement "If charles is less than 18 years old, how old is charles' father?" is TOTALLY UNNECESSARY as the father's age can be determined without even knowing Charles' age, as follows:
Let father's age be F, and Charles', C
Then C+=+F%2F3
Also,
Setting the equations equal to each other, we get: matrix%281%2C3%2C+F%2F3%2C+%22=%22%2C+3F%2F7+%2B+18%2F7+-+6%29
7F = 9F + 54 - 126 ------- Multiplying by LCD, 21
7F - 9F = 54 - 126
- 2F = - 72, and so, father's age, or: