A shopkeeper allows a discount of 10% on every item. Even after discount, he makes a profit of 80%. If a discount is not given, then profit % is?

66.66%

              CP      :        MRP                            

(100 - Discount) : (100 + Profit)

      (100 - 10)    :    (100 + 50)

              90       :       150 

               3        :         5

If discount not given then S.P. = MRP = 5R

Profit = 5R - 3R = 2R

P% = \(\frac{2}{3}\) × 100% = 66.66%