Formula for cell C9 (from instruction 4)

To get the cost of an item, we use VLOOKUP to search for the Product ID (PID) from the SALES sheet (Column A) in the PRODUCT sheet. Assuming Product IDs are in column A and Costs are in column B of the PRODUCT sheet.

$$\text{C9: } \boxed{\text{=VLOOKUP(A9, PRODUCT!A:B, 2, FALSE)}}$$

To compute the Total, multiply the Quantity (Column B) by the Cost (Column C).

$$\text{E10: } \boxed{\text{=C10*B10}}$$

To compute the discount, an IF statement with an OR condition is used. If the Total Cost (Column E) is greater than 300,000 OR the Quantity (Column B) is greater than 20, a 5% discount is applied to the Total Cost; otherwise, a 3% discount is applied.

$$\text{F5: } \boxed{\text{=IF(OR(E5>300000, B5>20), 0.05*E5, 0.03*E5)}}$$

To compute the final amount, subtract the Discount (Column F) from the Total (Column E).

$$\text{G13: } \boxed{\text{=E13-F13}}$$