A mother is 21 years older than her son.
In 6 years, she will be 5 times older than him.
THE QUESTION IS: WHERE IS THE FATHER?
If we call the age of the mother "X" and the age of the son "Y"
We can write: X=21+Y (because the mother is 21
years older than the son)
and since in six years the ages will be increased by 6 and since she will be 5
times older than him,
we can write: (X+6) = 5(Y+6)
SO: 21+Y+6 = 5Y+30
OR: 27+Y = 5Y+30
-3 = 4Y
Therefore Y = -3/4
-3/4 of What? Of a Year....
But: 1 Year = 12 months
So: Age of the son = -3/4 of 12 -9 Months....
WHERE IS THE FATHER?