Edexcel D1 2011 January — Question 6

Exam BoardEdexcel
ModuleD1 (Decision Mathematics 1)
Year2011
SessionJanuary
TopicCombinations & Selection

6. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{0360f78d-e18c-4c47-a2ec-ddd705a4175f-7_1214_1581_251_242} \captionsetup{labelformat=empty} \caption{Figure 6}
\end{figure} The graph in Figure 6 is being used to solve a linear programming problem. Two of the constraints have been drawn on the graph and the rejected regions shaded out.
  1. Write down the constraints shown on the graph. Two further constraints are $$\begin{aligned} x + y & \geqslant 30
    \text { and } \quad 5 x + 8 y & \leqslant 400 \end{aligned}$$
  2. Add two lines and shading to Graph 1 in your answer book to represent these constraints. Hence determine the feasible region and label it R . The objective is to $$\text { minimise } 15 x + 10 y$$
  3. Draw a profit line on Graph 1 and use it to find the optimal solution. You must label your profit line clearly.
    (3)