SOLUTION: A man's age is four times that me his son. Seven years ago his age was eleven times that of his son. How old are they now?

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Question 665558: A man's age is four times that me his son. Seven years ago his age was eleven times that of his son. How old are they now?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +f+ = Father's age now
Let +s+ = Son's age now
+f+-+7+ = Father's age 7 yrs ago
+s+-+7+ = Son's age 7 yrs ago
---------------------------
given:
(1) +f+=+4s+
(2) +f+-+7+=+11%2A%28+s+-+7+%29+
-----------------------
(2) +f+-+7+=+11s+-+77+
(2) +f+=+11s+-70+
Substitute (1) into (2)
(2) +4s+=+11s+-70+
(2) +7s+=+70+
(2) +s+=+10+
and, since
(1) +f+=+4s+
(1) +f+=+4%2A10+
(1) +f+=+40+
The father is 40 and the Son is 10
check answer:
(2) +f+-+7+=+11%2A%28+s+-+7+%29+
(2) +40+-+7+=+11%2A%28+10+-+7+%29+
(2) +33+=+11%2A3+
(2) +33+=+33+
OK