$1.$steady monthly demand fir the electrical power supply was $250$ units. the selling price of an electrical power supply unit was R$80000$ and a mark$-$up of $60\%$ on cost was used. all the sales are on credit and the collection period is $90$ days. collection costs approximately R$100$ per unit sold were incurred. the annual holding cost of an electrical power supply unit was $0\mathrm{.}24\%$ of the unit cost of the item. the cost of placing an order for electrical power supply units was R$5$ the cost of capital was $15\%.$

$1\mathrm{.}2$ xalculate the annual carrying costs based on EOQ. $($ ignore the opportunity co