Question 618676
let the mans age today be m. Let the son's age today be s
{{{m = 3s}}}
eight years ago, the man was {{{m-8}}} and his son was {{{s-8}}}
{{{(m-8)+(s-8) = 36}}} 
{{{m + s - 16 = 36}}}
{{{m + s = 52}}} substitute in the value for m from the first equation above
{{{3s + s = 52}}}
{{{4s = 52}}}
{{{s = 13}}} the son is 13 today
His Dad is 3*13 = 39