At the end of the tax year, The Revenue Office sent an inspector to audit the books of a local hospital. While the agent was checking the books, he turned to the executive of the hospital and said “I notice you buy a lot of bandages. What do you do with the end of the roll when there's too little left to be of any use?"
"Good question," noted the executive. "We save them up and send them back to
the bandage company and every once in a while, they send us a free roll."
"Oh," replied the auditor, somewhat disappointed that his unusual question had a practical answer. But on he went, in his obnoxious way. “What about all these plaster purchases? What do you do with what's left over after setting a cast on a patient?"
...
"Ah, yes," replied the executive, realizing that the inspector was trying to trap him with an unanswerable question...