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

Sept. $1$ Beginning inventory $29$ units @ $$18$

$5$ Sale $17$ units

$17$ Purchase $30$ units @ $$19$

$30$ Sale $30$ units

Assuming a perpetual inventory system and the first$-$in$,$ first$-$out method, determine $($a$)$ the cost of the merchandise sold for the September $30$ sale and $($b$)$ the inventory on September $30.$

a$.$ Cost of merchandise sold $fill in the blank $1$

b$.$ Inventory, September $30$ $fill in the blank $2$