Ichiro Problem
Grade: 3-12
It has been one month since Ichiro’s mother has entered the hospital. Ichiro decided to pray with his younger brother at a local temple every morning so that she will get better soon. There are 18 ten-yen coins in Ichiro’s wallet and just 22 five-yen coins in the younger brother’s wallet. They decided to take one coin from each wallet every day, put them in the offertory box, and continue to pray until either wallet becomes empty. One day when they were done with their prayer, they looked into each other’s wallets. The amount of money in the younger brother’s wallet was greater than Ichiro’s amount of money. When this happened, how many days had it been since they started their prayers?