Response to the following problem:
On March 15, 2015, Sudden Sales Co. purchased $5,000 of merchandize for cash.
Required: Assuming that Sudden Sales uses the periodic inventory system, calculate the cost of goods sold in each of the following circumstances:
1. Opening inventory, -0-; ending inventory, $2,000
2. Opening inventory, $3,000; ending inventory, $4,000
3. Opening inventory, $1,000; ending inventory, $1,500
4. Opening inventory, $2,000; ending inventory, -0-.