Question

Five years hence, the edge of Jacob will be three times that of his son. Five years ago,Jacob's edge was seven times that of his son. What are their present ages .

Answer 1

Let the age of Jacob and his son is $x$ and $y$.

As per 1^st condition of the question,

$x+3=3(y+3)$

$x=3y+6$ …….(1)

As per 2^nd condition of the question,

$x-5=7(y-5)$

$x=7y-30$

From equation 1^st and 2^nd,

$3y+6=7y-30$

$4y=36$

$y=9$

Put the value of y in equation 1^st, we get

$x=3\times 9+6$

$x=33$

Hence, the present age of Jacob is $33$ years and present age of his son is $9$ years.