Question 1075980
Let n be the amount of time it took the apprentice to finish a set of tankards. Then the master would take n-8 days. So:
1/n + 1/n-8=1/3
Then:
3(n-8)+3n=nē-8n
nē-14n+24=0
(n-12)(n-2)=0
n=12 or 2
Since 2-8=-6, we take 12 days as the time it took the apprentice to finish the task alone. So, figuring out the cost, it would take the master 4 days to finish, at $25/day=$100 total.
The apprentice takes 12 days, at $2/day=$24 total.
Together is 3 days @$27/day, or $81 total.  Those are the final costs for the tankards. ☺☺☺☺