Iq question based on your intelligence level....

Three friends in hotel ate dishes and bill was 75 ₹.now each head has to give 25₹each right.but owner told waiter to give 5₹back now at this time waiter kept 2₹for his pocket and gives 1₹each for three of them...so three friends given 24₹each means 72₹in total...and as I told 2₹for waiter.totally it becomes 74 .....now answer me where remaining 1₹ went???