5 Roland Neede, the baker, is making cupcakes. He makes three sizes of cupcake: miniature, small and standard. Miniature cupcakes are sold in boxes of 24 and each cupcake uses 3 units of topping and 2 decorations. Small cupcakes are sold in boxes of 20 and each cupcake uses 5 units of topping and 3 decorations. Standard cupcakes are sold in boxes of 12 and each cupcake uses 7 units of topping and 4 decorations. Roland has no restriction on the amount of cake mix that he uses but he only has 5000 units of topping and 3000 decorations available. Cupcakes are only sold in complete boxes, and Roland assumes that he can sell all the boxes of cupcakes that he makes. Irrespective of size, each box of cupcakes sold will give Roland a profit of \(\pounds 1\). Roland wants to maximise his total profit. Let \(x\) denote the number of boxes of miniature cupcakes, \(y\) denote the number of boxes of small cupcakes and \(z\) denote the number of boxes of standard cupcakes that Roland makes.

1. Construct an objective function, \(P\), to be maximised.
2. By considering the number of units of topping used, show that \(18 x + 25 y + 21 z \leqslant 1250\).
3. Construct a similar constraint by considering the number of decorations used, simplifying the coefficients so that they are integers with no common factor.
4. Set up an initial Simplex tableau to represent Roland's problem.
5. Perform one iteration of the Simplex algorithm, choosing a pivot from the \(x\) column. Explain how the choice of pivot row was made and show how each row was calculated.
6. Write down the values of \(x , y\) and \(z\) from the first iteration of the Simplex algorithm. Hence find the maximum profit that Roland can make, remembering that cupcakes can only be sold in complete boxes. Calculate the number of units of topping and the number of decorations that are left over with this solution.
7. The constraint from the number of units of topping can be rewritten as \(18 P + 7 y + 3 z \leqslant 1250\). Form a similar expression for the constraint from the number of decorations. Use this to find the number of boxes of small cupcakes which maximises the profit when there are no decorations left over. Find the solution which gives the maximum profit using all the topping and all the decorations, and find the values of \(x , y\) and \(z\) for this solution. \href{http://physicsandmathstutor.com}{physicsandmathstutor.com}