Question 1172530
Therasa's rate,  {{{1/15}}}.
Rowena's rate,  {{{1/w}}}.
Combined rate of both, {{{1/15+1/w}}}.


Question based on 1 job.


{{{(1/15)3+(1/15+1/w)*4=1}}}

{{{3/15+4/15+4/w=1}}}

{{{7/15+4/w=1}}}

{{{7w+15*4=15w}}}

{{{60=15w-7w}}}

{{{60=8w}}}-----------{{{15=2w}}}

{{{highlight(w=7&1/2)}}}