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Six years ago, a man was six times as old as his son. In six years time, he will be three times as old as him. Find the ages of the man and the son
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From the condition,
m - 6 = 6*(s-6), (1)
m + 6 = 3*(s+6). (2)
where m = man's present age, s = son's present age. Simplify and solve:
m - 6 = 6s - 36, (3)
m + 6 = 3s + 18. (4)
Distract (4) from (3). You will get
-12 = 3s - 36 - 18,
-12 + 36 + 18 = 3s,
42 = 3s,
s = = 14.
Then from (1) m = 6*(s-6) + 6 = 6*(14-6) + 6 = 6*8 + 6 = 54.
Answer. Man's present age is 54 years. Son's present age is 54.