4 Derrick, a tanker driver, is required to deliver fuel to 6 different service stations \(A , B\), \(C , D , E\) and \(F\).
Derrick needs to begin and finish his delivery journey at the refinery \(O\).
The distances, in miles, between the 7 locations which have a direct road between them are shown in the network below.
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Derrick spends 30 minutes at each service station to complete the fuel delivery.
When driving, the tanker travels at an average speed of 40 miles per hour.
The minimum total time that it takes Derrick to travel to and deliver fuel to all 6 service stations, starting and finishing at the refinery, is \(T\) minutes.
4
- Using the nearest neighbour algorithm starting from the refinery, find an upper bound for \(T\)
4 - Before setting off to make his fuel deliveries, Derrick is notified that, due to a low bridge, the road represented by CE is not suitable for tankers to travel along.
State, with a reason, the effect this new information has on your answer to part (a).
[0pt]
[2 marks]