If cost price of an item is 90% of its selling price, then what is th…

Cost Price (C) = 90% of Selling Price (S)

C = 0.9S

P% = 100* Profit/C

P% = 100* (S-C)/C = 100* (S-0.9S)/0.9S = 100* 0.1/0.9 = 100/9

The correct answer is Option (1) → $11\frac{1}{9}$%