Ice Cream Sundae!!!

This is from an old story, back in the '90s, in the days when an ice cream sundae cost much less. A 10 year-old boy entered a hotel coffee shop and sat at a table. A waitress put a glass of water in front of him

"How much is an ice cream sundae?" the little boy asked.

"Twenty Five Rupees," replied the waitress.

The little boy pulled his hand out of his pocket and studied the bucks he had. "Well, how much a plain ice cream cost?" he inquired.

At the same time, more people were waiting for a table and the waitress was getting very impatient. "Fifteen Rupees," she roughly replied.

The little boy again counted the bucks he has. "I'll have the plain ice cream," he said.

The waitress brought the ice cream, put the bill on the table and walked away. The boy finished the ice cream, paid the cashier and left. When the waitress came back, she began to cry. As she wiped down the table, there placed neatly beside the empty dish were "Ten Rupees". 

You see, he couldn't have the sundae because he had to have enough money to leave her a tip.............!!!!!