A shopkeeper by selling 5 items earns a profit equal to the selling price of one item. What is his/her profit percentage?

25%

Let the selling price be a

Five items sold at Rs. 5a

Now given profit is equal to selling price of 1 article = a

= CP = SELLING PRICE - PROFIT = 5a - a = 4a

= Profit percentage can be given as = a × 100/4a = 25%