A shopkeeper earns a profit of 12% on selling a book at 10% discount on the printed price. The ratio of the cost price and the printed price of the book is

Let the CP of book = ₹ P
Then, SP of book = {(100 + 12) x P}/100 = 112P/100
Now, the printed price = ₹ Q
Then, after discount,
the SP = (100 - 10)Q/100 = 90Q/100
Since, both SP are same.
Then, 112P/100 = 90Q/100
⇒ P/Q = 45/56
⇒ 45 : 56