The tramp convinced the highway man, to give him the pistol by ___

Directions: Read the given passage and answer the following question:

A tramp was one day walking on a country road when he suddenly met a highway man. Pointing a pistol, the man exclaimed, “Your money or your life.”
“My friend,” said the tramp, “I cannot deliver my money for I should be helping you in evil doing. However, exchange is lawful. I will give you my purse for the pistol.”
The robber agreed and said, “That is right. I shall give you my pistol and you will give me your purse.”
The exchange took place. As soon as the tramp received the pistol, he pointed the pistol at the robber’s head and said, “Now, my friend, my purse back or the weapon may go off.”
“Fire!” said the robber, “There is no powder in the pistol.”