A shopkeeper earns a profit of 16% if he allows a discount of 20% on the marked price of an article. What will be the profit percent earned by the shopkeeper if he sold the article at its marked price?

U need the concept of n/d and n/d+n for this
Assume cost price as 100 hence selling price becomes 120 now the discount is 1/5 from marked price that's how we got the selling price
To make this selling price into marked price again increase it by 1/6 i.e multiply by 7/6 u get 135.33 hence 35.33 percent profit.hope this helps