$($D$)$ Delta Company produces mobiles and purchases batteries at $$30$ per unit.

The management proposes producing the batteries instead of purchasing them.

The annual quantity of batteries is $50,000$ units.

The costs of producing the batteries are:

$$20$ variable cost per unit,

The company will pay an annual rent of $$250,000$ to rent a new machine to produce the batteries.

The general $($old$)$ fixed cost for the company is $$500,000.$

Do you advise the company to produce the batteries or to purchase it$?$ Justify?

$($E$)$ Nile Co$.$ can produce $2$ products, $A$ & B; the following data is estimated to help in preparing the production plan for the coming period to maximize the profit:

$\backslash$table$[[,$A$,$B$],[$Price$,$$$30,$$$50$