Where is that 1 rupee?

Three friends went to a hotel.
The bill was Rs.75/-
Each one contributed Rs.25/-.
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.25/-. Now as they are given 1 rupee back, their contribution reduces to Rs.24/-.
They all contributed Rs.24/-.
That is 24×3=72 & 2 rupees are in the waiter’s pocket.
The total becomes 74. But they had paid Rs.75/-.
Where is the remaining 1 rupee?????????