GCE Financial Accounting 1990 Question 13

Use the following information extracted from TOM's books:
Stock at 1st January 1901: ₦6,500
Stock at 31st December 1901: ₦5,500
Creditors at 1st January 1901: ₦4,000
Creditors at 31st December 1901: ₦5,000
Cash paid for goods during the year: ₦20,000
Gross Profit: 25% on cost.
Administrative and selling expenses: ₦2,750

Calculate the percentage of net profit on sales

1. A.25%
2. B.22%
3. C.21%
4. D.20%
5. E.10%.