A product$$s unit cost includes $$50$ for direct materials used, $$40$ for direct labor incurred, $$30$ for manufacturing overhead applied, and its unit selling price is $$300.$ Depreciation is $$1,500$ and general, selling, and administrative expenses are $$1,200.$

$($a$.)$ Calculate the product$$s cost per unit.

$($b$.)$ Calculate the gross margin per unit.

$($c$.)$ Calculate the gross margin ratio.

$($d$).$ Calculate the net income if $25$ products are produced and sold.