Beginning inventory, purchases, and sales for an inventory item are as follows:

Sep. $1$ Beginning Inventory $25$ units @ $$15$

$5$ Sale

$12$ units

$17$ Purchase

$28$ units @ $$18$

$30$ Sale

$14$ units

Assuming a perpetual inventory system and the last$-$in$,$ first$-$out method:

a$.$ Determine the cost of goods sold for the September $30$ sale.

$

b$.$ Determine the inventory on September $30.$