We have to calculate each option and then the other 2 questions below the table. I have no other information as this is what I was given.

Case study 2: Keeping up the Quality I am the manager of a colliery which produces 20,000 tonnes of coal a week, but is currently experiencing quality problems. My main customer, the local power station, requires coal with a minimum calorific value (CV-equivalent to energy content) of 24 gigajoules per tonne (Gj/t). Unfortunately, at the moment I can only produce coal, using my normal coal preparation techniques, at 23Gj/t. The easiest solution is to buy in better quality coal ("sweetener") to mix (blend) with my own. I can then sell the blended product to the power station for 1.20/Gj, less a transport cost of 2.00/tonne (note: coal is usually sold by the Gj, not by the tonne, as it is the energy content that the customer wants; other costs, such as transport, usually depend on the weight). I have to buy the sweetener and transport it to my colliery, and the costs vary depending on where I buy it from. My choices are: Option SourceGrade CV (G/t) Cost Transport (E/t) 1.20 1.20 2.50 2.50 4.50 4.50 Colliery A Washed smalls 2 Collery A Singles 3 4 5 Colliery B Washed smalls Colliery B Singles Colliery C Singles Colliery C Doubles 25.0 1.20 27.6 1.40 25.5 1.20 28.3 1.40 29.21.40 31.0 1.55 There is a further cost for blending the two coals together of 50p per tonne of coal blended. What is my best strategy? Why is this? As an alternative, I can adopt a different coal preparation technique. This is expensive (6.00 per tonne of input) but will increase the calorific value to 24.5G/t for a loss of 7% in tonnage (that is, if l treat 100 tonnes at 23G/t, l end up with 93 tonnes at 24.5Gj/t). I do not have to treat all the output this way Is this better than blending? Stop Press: the power station has rung to say that, because of problems with its sales of electricity, it is unable to take more that the contractually agreed amount of 20,000 tonnes a week from me. Now what do I do? How much does this cost me, compared with my previously optimal solution