A seller earns a profit of 10% after selling an object at 10% discount. What is the ratio of cost price to the printed price of the object ?

9 : 11

When any article is sold at discount after gaining the profit also, then

CP : MRP = (100 - discount) : (100 + Profit)

              = (100 - 10) : (100 + 10)

              = 90 : 110 = 9 : 11