In detail

Where is the father?

Where is the father?


Today a mother is 21 years older than her son. In 6 years the child will be 5 times younger than his mother.

Where is the father?

EYE: It has a solution, think a bit.

Solution

Suppose the child has today X years and the mother is Y years
- Therefore it is fulfilled that: X + 21 = Y

- The following will be accomplished within 6 years:
5 * (X + 6) = Y + 6

We replace Y in the second equation for the value it has in the first and we have:
5 * X + 30 = X + 21 + 6

Simplifying we have:
4 * X = -3

Where we deduce that:
X = -3/4

So the child is today -3/4 of a year or -9 months or what is the same 9 months to be born, so ... they are conceiving it at that time, therefore ...
The father has to be on top of the mother!