Question 354392
{{{m = 5s}}} and {{{2s = m/2 -3}}}, by the given.
Then by direct substitution,
{{{2s = (5s)/2 - 3}}}.  Then,
{{{3 = (5s)/2 -2s}}},
{{{3 = s/2}}}, and so by cross-multiplication, {{{s = 6}}}.
The mom is {{{m = 5*6 = 30}}} years old.