Question 128525
These carpenters work at the rate of one shed per 80 man-days(4*20).

1 carpenter takes 80 days
2 carpenters takes 80/2=40 days
3 carpenters takes 80/3=26 2/3 days
4 carpenters takes 80/4=20 days
5 carpenters takes 80/5 days
6 carpenters takes 80/6=13 1/3 days

Hope this helps-----ptaylor