As it did not fulfill the number of vehicles being 10, number of cars might need to be modified to accommodate the number of bikes in order to reach the requirement of 10 vehicles. It is known that the number of wheels of one car is double that of one bike. When the number of cars was reduced by 1, the number of bike would increase by 2. At this time, the number of wheels still remains 32. As it is difficult to demonstrate this process by using word representation, the students thus adapted graphic representation method.