D1 June 2011 Q5

EdexcelOld spec10 marksRoute Inspection

5.

Figure 5: network with arcs GF 8, GD 5, GE 7, GC 9, FE 3, FB 7, EC 5, EB 5, BC 5, CD 7, CA 9, DA 17, BA 11
Figure 5

[The total weight of the network is 98 km]

Figure 5 models a network of gas pipes that have to be inspected. The number on each arc represents the length, in km, of that pipe.

A route of minimum length that traverses each pipe at least once and starts and finishes at A needs to be found.

(a) Use the route inspection algorithm to find the pipes that will need to be traversed twice. You must make your method and working clear. (5)
(b) Write down a possible shortest inspection route, giving its length. (2)

It is now decided to start the inspection route at D. The route must still traverse each pipe at least once but may finish at any node.

(c) Determine the finishing point so that the length of the route is minimised. You must give reasons for your answer and state the length of your route. (3)
‹ Previous26 of 39 in Route InspectionNext ›