Northwest University is in the process of complet- ing a computer bus network that will connect com- puter facilities throughout the university. The prime objective is to string a main cable from one end of the campus to the other (nodes 1-25) through underground conduits. These conduits are shown in the network below; the distance between them is in hundreds of feet. Fortunately, these underground conduits have remaining capacity through which the bus cable can be placed.

(a) Given the network for this problem, how long (in hundreds of feet) is the shortest route from node 1 to node 25?

(b) In addition to the computer bus network, a new phone system is also being planned. The phone system would use the same underground conduits. If the phone system were installed, the follow- ing paths along the conduit would be at capacity and would not be available for the computer bus network: 6-11, 7-12, and 17-20. What changes (if any) would you have to make to the path used for the computer bus if the phone system were installed?

5 8 15 10 5 14 18 2 8 22 6 7 11 5 6 9 3 6 15 19 8 1 7 23 8 10 12 5 6 25 20 10 16 A 6 8 8 13 15 17 17 24 10 10 9 21