A manufacturing business makes a product in two models, model M$5$ and Model M$6.$ Details of the two products are as follows.

$\backslash$table$[[,$Model M$5,$Model M$6],[$Annual sales,$8,000$ units,$8,000$ units$],[$Number of sales orders,$60,250],[$Sales price per unit,K $54,$K $73],[$Direct material cost per unit,K $11,$K $21],[$Direct labour hours per unit,$2\mathrm{.}0$ hours,$2\mathrm{.}5$ hours$],[$Direct labour rate per hour,K $8,$K $8],[$Special parts per unit,$2,8],[$Production batch size,$2,000$ units,$100$ units$],[$Setups per batch,$1,3],[,,],[,$K$,$Cost Driver$],[$Setup costs,$97,600,$Number of setups$],[$Materials handling,$42,000,$Number of batches$],[$Special part handling costs,$50,000,$Number of special parts$],[$Invoicing$,31,000,$Direct labour hours$],[$Other overheads,$108,{000}_{?},],[$Total overheads,$328,{600}_{?},]]$

A customer has indicated that an interest in placing an order for either model M $5$ or M $6$ and the sales manager wished to sell the higher$-$priced model M$6.$

Required:

$($a$)$ Calculate the profit per unit for each model, using ABC.

$(10$ Marks$)$