By selling an article at 80 % of its marked price, a trader makes a loss of 10 %, what will be a profit percentage, if he sells it at 95 % of its marked price?

Let marked price = ₹ 100
And selling price = ₹ 80
In condition of 10% loss the cost price of article = (80 x 100)/90 = ₹ 800/9
According to the question,
When SP = 95, then
∴ Required profit percentage = [{95 - (800/9)} / (800/9)] x 100 = 55/8
= 6.9% (approx)