Correct option is B
Let's assume the cost price of each article is 'C'.
Selling Price of 7 Articles: = Cost Price of 6 Articles = 6C
Selling Price of 1 Article: = (6C) / 7
Loss per Article: = Cost Price - Selling Price = C - (6C) / 7 = (C / 7)
Percentage Loss: = (Loss per Article / Cost Price) x 100 = [(C / 7) / C] x 100 = (1/7) x 100 =