Question 946457
Look at the time in hours for 1 job.  Each man has the rate of r job per hours.


For n men working the rate is n*r.


Handle the question first by looking for how many hours for the three men.
{{{3r*t=1}}}, for the one job, and this must be the same quantity of job as {{{4r*(10*6)=1}}}.


Remember, for now, t is how many HOURS of work.
{{{highlight_green(3rt=4r*60)}}};
{{{t=(4*60)/3}}}
{{{t=4*20}}}
{{{highlight_green(t=80)}}}, HOURS.


This is 10 days, because as given, 8 hours per day.