Example $5\mathrm{.}3$

Trapvas Ltd manufactures men's shoes. Its level of activity is currently $60\%.$ The enterprise $1000$ abtains an order from a neighbouring state several thousand kilometres away to supply prise's directors shoes, size $x,$ within $30$ days at R$60$ free on rail $($for$).$ Some of the entercost per pair to manufacture is as follows:

$\backslash$table$[[$Variable costs:,R$],[$Direct material,$12],[$Direct labour,$24],[$Manufacturing overheads,$12],[$Marketing costs,$8],[$Fixed costs:,$4],[$Manufacturing overheads,$2],[$Administrative costs,$2_{?}$