Money

Peter and Susan were friends. One day, Susan requested Peter to bring her a fruit juice. She gave him $1. Peter went to the nearest shop and asked the Shopkeeper for a fruit juice. The shopkeeper asked for $2 which was the cost of 1 fruit juice. Peter thought that he could contribute $1 from himself and he pulled $1 coin and add them to $1 to make it $2 and bought the fruit juice for her friend.