A company that uses a perpetual inventory system made the following cash purchases and sales. There was no beginning inventory.(2 marks)

January 1:	Purchased 100 units at SAR10 per unit
February 5:	Purchased 60 units at SAR 12 per unit
March 16:	Sold 40 Units for SAR 16 per unit

1. Explain the four inventory valuation methods.
2. Prepare general journal entries to record the March 16 sale using the
   1. FIFO inventory valuation method.
   2. LIFO inventory valuation method.