Question 830551
{{{Rate*time=job}}}
The rate of work is best stated in units of jobs per time.


Unknown time for the apprentice to do 1 job.  Let this time be x.
Mason, {{{1/(x-6)}}}
Apprentice, {{{1/x}}}
Both together, {{{highlight(1/(x-6)+1/x=1/4)}}}, because together, their rate is one job in four hours.


Solve for x and you can find both of their individual rates.