A large state university uses 3-digit mail stops to code mail on campus. The initial step in sorting this mail is to sort according to the first digit (there are 10 possible) which signifies a general campus zone. This step is accomplished by pushing a key with corresponding number, which dumps the letter in an appropriate bin. A typical mail sorter can sort 60 envelopes per minute and it takes a minimum of 0.3 seconds to just push the key with cognitive processing involved.

a) Assuming that the mail is distributed evenly over the campus zones, what is the mail sorter's bandwidth?

b) After a while the sorter notices that campus mail is distributed as follows. If the mail sorter used this information, how many pieces of mail could the sorter possibly handle in one minute?

Zone % Distribution 25 15 25 5 1 2 3-9