Question 806103
The two tricks are to define the meaning of 1 job, and calculate the one-man work rate.


The meaning of 1 job is, " dig a hole 3 metres long, 3 metres wide and 3 metres deep,".  This will give the size of the hole, meaning The Job.


The question part will also be some quantity of job, in that case, 6*6*6.  If one job is a hole 3*3*3, then how many job is 6*6*6?  The job quantity asked is {{{6*6*6/(3*3*3)=2^3=8}}} jobs.


If 2 men need 3 hours to do 1 job,
then
1 man needs 2*3=6 hours to do this 1 job.  The one-man rate is {{{1/6}}} Hours per Job.


Thinking for this again, if the same two men are to do 8 jobs, these same two men still have their already-given rate of {{{1/3}}} jobs per hour FOR THE TWO MEN WORKING TOGETHER.


rate*time=jobs
{{{highlight((1/3)*h=8)}}}--------if this equation makes sense to you then you can finish, finding h for hours to do the 8 jobs.