Three friends went to a hotel. The bill was Rs 30/- Each one contributed Rs.10/-. The waiter took the bill to the cashier. The cashier was happy & decided to give them a discount of Rs.5/- & asked the waiter to return them Rs.5/-. Now the waiter was confused.

 

How to distribute Rs 5 among 3 persons? He kept Rs 2 in his pocket & gave one rupee to each one of the 3 persons.

 

So initially each one had contributed Rs.10. Now as they are given 1 rupee back, their contribution reduces to Rs 9. They all contributed Rs 9 — that is 9×3=27 & 2 rupees are in the waiters pocket. The total becomes 29.

 

But they had paid Rs 30. Where is the remaining 1 rupee?.