Question 813620
8 man hours for 6 quarts
8/3=2 2/3 hours 2 hours 40 minutes

explanation:
When all four are working it takes 2 hours each. That is 4*2=8 man hours of work. In this type problem we assume each person works at the same rate.
Now that Joe left we have 3 people who have to work 8 man hours total to pick another 6 quarts.
that is 8/3 =2 2/3 hours  which is 2 hours 40 minutes.