3 QUESTIONS I have the answer need explanation how to get it

1.) Franklin Industries employs a five-day work week and a December 31 year end. Normal weekly salaries amount to $48,000. If December 31 ends on a Wednesday, what is the adjusting entry on December 31? the answer is below can you explain how to get this

Salaries Expense	$28,800
Salaries Payable		$28,800

2.) If goods in transit are shipped FOB Shipping Point: the answer is: The buyer has legal title to goods as soon as they are shipped. can you explain how

3.) If the oldest items purchased are in ending inventory at the end of the period, which inventory costing method is being used? the answer is: LIFO. can you explain how