According to the charging standard of Beijing Hongqiao Tianya Parking Lot, the charging standard for cars during the day (7: 00- 19: 00) is 15 yuan/hour, and the charging standard for big cars is 20 yuan/hour. At night (19: 00-7: 00), the charging standard for cars is 1 yuan/hour, and the charging standard for carts is 2 yuan/hour.