Posted by Mathematics on Wednesday, January 11, 2012 at 8:35am.
In four years' time, a father will be three times as old as his son. Six years ago, he was seven times as old as his son. How old are they now? Explain your workings. Thanks

Kathie  Reiny, Wednesday, January 11, 2012 at 8:50am
son's present age: x
father's present age : y
4 yrs from now:
son : x+4
father : y+4
y+4 = 3(x+4)
y = 3x + 8
6 yrs ago:
son : x6
father: y6
y  6 = 7(x6)
y = 7x 36
so 7x 36 =3x+8
4x = 44
x = 11
y = 3(11)+8 = 41
The son is now 11 and the father is now 41
check:
4 yrs from now: son 15, father 45
3 times as old? yes
6 yrs ago: son  5, father 35
7 times as old? yes
all is good

Kathie  Mathematics, Wednesday, January 11, 2012 at 10:01am
Thank you very much Reiny!
Answer This Question
Related Questions
 algebra  in four years's time a father will be three times as old as his son. ...
 math  A father is now three times as old as his son, twelve years ago he was ...
 Mathematics  Two years hence,a father will be six times as old as his son.Three...
 algebra  The combined age of a father and his two sons is 50 years. Four years ...
 algebra  Seven years ago a women was four times old as her sons age at that ...
 Math  The sum of the ages of a father and his son is 62 years. 15 years ago, ...
 math  When a woman is as old as her father is now, she will be five times as ...
 MATH  1. A father is three times as old as his son. Five years ago the sum of ...
 Math  Ten years ago a man was three times as old as his son. In twelve more ...
 Algebra  Ten years ago a man was three times as old as his son. In twelve more ...
More Related Questions