“Oh, how clumsy of me. Never mind, if you look into the bag for the one that is left, you will be able to tell which pebble I picked.”
He decided to offer the businessman a deal that would completely wipe out the debt he owed him. However, the catch was that we would only wipe out the debt if he could marry the businessman’s daughter.
She drew out a pebble from the bag, and before looking at it ‘accidentally’ dropped it into the midst of the other pebbles.
She said to the loan-shark:
The pebble left in the bag is obviously black, and seeing as the loan-shark didn’t want to be exposed, he had to play along as if the pebble the daughter dropped was white, and clear her father’s debt.