A company has the following information about its inventory for the month of January 2023:

Beginning inventory: $20,000
Purchases during the month: $30,000
Ending inventory: $15,000
The company uses the FIFO inventory costing method. In addition, the company had sales revenue of $50,000 during the month of January. The company's gross profit percentage is 60%.

a) Calculate the cost of goods sold for the month of January.

b) Calculate the gross profit for the month of January.

c) If the company had used the LIFO inventory costing method instead of FIFO, would the cost of goods sold be higher or lower? Explain your answer.