Question 1148629
x, variable time hours

RATES 1/4 for bob, 1/2 for alan


{{{(1/4)*1+(1/4+1/2)x=1}}}
-
{{{1/4+(1/4+1/2)x=1}}}

{{{1+(1+2)x=4}}}

{{{3x=3}}}

{{{highlight(x=1)}}}

They both worked together for one hour.  One hour past 4pm is  5pm.


They both finished at {{{highlight(5pm)}}}.