2) An operator is going to buy a grain drill. The choices available are: 10, 20, or 30 foot.

Field efficiency is 70% for the 10 foot and 20 foot drill, and 65% for the 30 foot drill. Speed would be 6 mph for all three. Suppose the operator wants to be able to cover 400 acres in 3 days and can work at this task 12 hours per day. 

a) Calculate the minimum capacity needed.

b) Now calculate field capacity for the three grain drill sizes.

c) What is the minimum size grain drill that will meet this target?

d) Suppose the operator can allocate 4 days to this task. What is the minimum size drill that would accomplish that goal?

e) If the operator was willing to work only 10 hours per day, what is the minimum required field capacity?