1. (16 points) Kolya, after walking a quarter of the way from home to school, realized he had forgotten his workbook. If he does not go back for it, he will arrive at school 5 minutes before the bell, but if he does go back, he will be one minute late. How much time (in minutes) does the journey to school take?
# Answer: 12 min

Solution. The extra $2 / 4$ of the journey takes 6 min. Therefore, the entire journey to school will take 12 min.