Beginning inventory, purchases, and sales for Item Zeta$9$ are as follows:

$\backslash$table$[[$Oct$.1,$Inventory,$38$ units @ $$20],[7,$Sale,$29$ units$],[15,$Purchase,$27$ units @ $$21],[24,$Sale,$17$ units$]]$

Assuming a perpetual inventory system and using the first$-$in$,$ first$-$out $($FIFO$)$ method, determine $($a$)$ the cost of the goods sold on October $24$ and $($b$)$ the inventory value on October $31.$

a$.$ Cost of the goods sold on October $24$

b$.$ Inventory value on October $31$