One day, a mango vendor stopped near a paan shop and thought, "Oh! I want to eat a paan, but I don't have any money with me."
By then, the paan seller had also seen the mango vendor. He thought, "Oh! Such lovely mangoes. I wish I could eat one of those juicy ones."
So the paan seller shouted out to him, "Hey, will you exchange a mango for a paan?"
The mango vendor agreed. But the paan seller took some rotten betel leaves and made a tiny paan. He gave it the mango vendor. When the mango vendor asked for chuna, he replied, "Go and rub the paan against the wall to get chuna."
The mango vendor realized that he was being cheated. He gave a green mango to the paan seller. On seeing the green mango, the paan seller said, "Give me a yellow mango."
The mango vendor replied, "Rub your mango against that yellow painted wall and you will get your yellow mango."