SOLUTION: 4 years ago i was half as old as my father. Six years hence, I will be three fifths as old as he. How old am I now?

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Question 1146172: 4 years ago i was half as old as my father. Six years hence, I will be three fifths as old as he. How old am I now?
Found 2 solutions by josgarithmetic, greenestamps:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Ages s and f

system%28s-4=%281%2F2%29%28f-4%29%2Cs%2B6=%283%2F5%29%28f%2B6%29%29

2s-8=f-4
f=2s-8%2B4
f=2s-4


subst into secnd eq
5s%2B30=3f%2B18
5s-3f=18-30
5s-3%282s-4%29=-12
5s-6s%2B12=-12
-s=-24
highlight%28s=24%29







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Is "i" and "I" the same person?

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


Ages now:
son x
father y

Ages 4 years ago:
son x-4
father y-4

Ages 6 years from now:
son x+6
father y+6

Using those expressions for the numbers in the problem, write two equations that reflect the given information:

the son's age 4 years ago was 1/2 the father's age 4 years ago: x-4+=+%281%2F2%29%28y-4%29

the son's age 6 years from now will be 3/5 the father's age 6 years from now: x%2B6+=+%283%2F5%29%28y%2B6%29

That gives you two linear equation in x and y; solve them by your favorite method.

Note that the problem only asks for the son's age. Since you don't need to find the father's age (y), choose a method that solves for x first.