Additional information:

$$ Each aircon comes standard with a $1$ year warranty, as required by legislation.

$$ Customers may also extend an aircon warranty at a cost of R$250$ per year, up to a maximum of $3$ years.

$$ None of the customers above chose to extend their warranty.

$$ The normal price of an aircon is R$4000$ each.

$$ Delivery is considered necessary to fulfil each sale transaction. Customers who choose to collect aircons at A Ltd$$s premises are not compensated for their delivery costs.