Mathematical problems of oil pouring
First, collect all the oil in the oil tank that can hold 10 kg, then fill the oil basket with a gourd twice, and continue to pour into the oil tank until it is full. At this time, the amount of oil in each container is: in the oil basket:10-3-3 =1(kg); Hululi: 3- 1=2 (kg); Inside the fuel tank: 3+3+ 1=7 (kg). On the basis of the existing oil in each container, pour all 7 kilograms of oil in the oil tank into the oil basket, so that the oil in the oil basket becomes 8 kilograms. Then pour all 2 Jin of oil in the gourd into the fuel tank. Then put the gourd (3 kg) in the oil basket. In this way, the oil in the oil basket becomes: 8-3=5 (kg).