SOLUTION
The rate at wihich the cartons are packed per hours is

Then we find the rate at which each of the worked per hour.
The number of carton joe parcked=6
The ime taken by Joe =2 hours

Hence
Joe packed 3 cartons per hour
Similarly,
The number of carton Bob packed =17
The time taken by Bob =6 hours
hence

hence
Bob packed 2.83 cartons per hour
Hence
Comparing the number of carton packed per hour by both individuals,
Joe packed the most carton per hour