Edexcel D2 2018 June — Question 1

Exam BoardEdexcel
ModuleD2 (Decision Mathematics 2)
Year2018
SessionJune
TopicNetwork Flows

  1. Table 1 shows the cost, in pounds, of transporting one unit of stock from each of four supply points, \(\mathrm { A } , \mathrm { B } , \mathrm { C }\) and D , to each of four demand points, \(1,2,3\) and 4 . It also shows the stock held at each supply point and the stock required at each demand point. A minimum cost solution to this transportation problem is required.
\begin{table}[h]
1234Supply
A2432213427
B2831293741
C2541333531
D2332313614
Demand33352520
\captionsetup{labelformat=empty} \caption{Table 1}
\end{table} Table 2 shows an initial solution given by the north-west corner method. \begin{table}[h]
1234
A27
B635
C0256
D14
\captionsetup{labelformat=empty} \caption{Table 2}
\end{table}
  1. Explain why a zero has been placed in cell C 2 in Table 2. State the other cell in Table 2 in which the zero could have been placed.
  2. State the shadow costs clearly and enter the improvement indices into Table 3 in your answer book. Taking the most negative improvement index to indicate the entering cell,
    [0pt]
  3. list the stepping-stone route that should be used to obtain the next solution. You should make clear the cells that are included in your route and state your entering and exiting cells. [You do not need to state the next solution. You do not need to solve this problem.]