Accounting ratio - What is G.O.P ?

G.O.P. = G.P. Ratio
= Gross Profit / Sales x 100%
= [(Sales - Cost of Sales) / Sales] x 100%

e.g. Sales = 100, Cost of Sales = 80, Gross Profit = 20
then G.P. Ration = [(100 - 80) / 100] x 100% = 20%

VERY DIFFICULT !!