Math
posted by Mia on .
I cant figure this out! Can someone please tell me were my mistake is?? :)
 a man is 3 times as old as his son. In 11 years time he will be twice as old as his son will be.
Let s represent sons age in years now
I did: present man: 3s son: s
In 11 years man: 2(s+11). Son: s+11

I tried alot and finally got the answer :) thanks anyways

I always found that these are easy when the information is restated in different cases
present:
son's age  x
man' age  3x
in 11 years from now:
son's age = x+11
man's age = 3x+11
it said, at that time the man is twice as old as his son
3x+11 = 2(x+11)
3x + 11 = 2x + 22
x = 11
The son is now 11, and the man is now 33
check:
now son is 11, man is 33
in 11 years:
son is 22 , man is 44
is the man twice as old as his son at that time ?
YES. 
A man is four times as old as his son. In 6 years he will be three times as old. The son present age is what?