Waqar Sound uses a periodic inventory system. One of the stores products is a wireless headphone. The inventory quantities, purchases, and sales of this product for the most recent year are as follows:

	Number of units	Cost per Unit	Total Cost
Inventory, Jan 1	10	150	Rs 1500
First Purchase	30	101	3030
Second Purchase	40	140	5600
Third Purchase	5	110	550
Fourth Purchase	15	130	1,950
Good available for sale	100
Units sold during the year	80
Inventory, Dec 31	20

Instructions

a. Using periodic costing procedures, compute the cost of the December 31 inventory and the cost of goods sold for the year under each of the following cost assumptions:

1. First-in, first-out.

2. Last-in, first-out.

3. Average cost (round to the nearest dollar, except unit cost).