Question 906444
t takes Austin 10 hours to paint a fence alone.
 Ashley can do the same job in 13 hours.
If Austin paints alone for 35 minutes before Ashley begins helping, how long must they work together to finish painting the fence?
:
Convert 35 min to hrs, 35/60 = {{{7/12}}} hrs
let t = time required to complete the job when working together
then
(t+{{{7/12}}}) = Total time worked by Austin
:
Let the completed job = 1
:
A shared work equation
{{{((t+(7/12)))/10}}} + {{{t/13}}} = 1
multiply equation by 130, cancel the denominators and we have
13(t+{{{7/12}}}) + 10t = 130
13t + {{{91/12}}} + 10t = 130
23t = 130 - {{{91/12}}}
t = 122{{{7/12}}} * {{{1/23}}}
t = {{{1471/12}}} * {{{1/23}}}
t = {{{1471/276}}} 
t = 5{{{91/276}}} hrs working together