Question 877035
w breadth, L length.
Their ratio is given as {{{w/L=3/5}}}, then {{{w=(3/5)L}}}.


Perimeter goes by {{{2w+2L=160}}}, simplifying to {{{w+L=80}}}.
Substitute for w:
{{{(3/5)L+L=80}}}
{{{3L+5L=400}}}
{{{8L=400}}}
{{{highlight(L=50)}}}
Use that to compute w.
{{{w=(3/5)*50}}}
{{{highlight(w=30)}}}.