1. The total number of bicycles and cars represents the total number of both, just like the total number of chickens and rabbits.

2. Assume that 8 cars are all cars, which is (8* 4-28) different from the actual number of wheels, and then use (8* 4-28)÷ (4-

3. Assume that all eight bicycles are different from the actual number of wheels \, (28-8* 2), and then use (28-8* 2)÷ (