A firm using FIFO had a beginning inventory of $48,000, an ending inventory of $56,000, and a pretax income of $400,000. If it had used LIFO, its beginning inventory would have been $20,000, its ending inventory would have been $16,000, and its pretax income would have been:

I understand that 388,000 is the correct answer. But I dont know how to get there. Please help. Thanks