hey guyz here i share a marvelous idea, the idea is a modern day vending machine to solve the Indian problem of change (chutte paise) not being available in small retail shops. to sort this we propose the idea of 'Ex'-Change a modern vending machine. whenever a customer puts a rupee coin of 1, 2, 5 rupees, he gets a discount coupon of 5-10%. now when he purchases something from retail shop, he gets discount of that amount on his total bill.