10. In the garage, there are several two-wheeled motorcycles and four-wheeled sedans. The ratio of the number of vehicles to the number of wheels is $2: 5$. What is the ratio of the number of motorcycles to the number of sedans?
10.【Solution】In the garage, on average, there are 5 wheels for every 2 cars, which means there are 10 wheels for every 4 cars. Simple trial and error can show that 1 sedan and 3 motorcycles have exactly 10 wheels. Therefore, the ratio of the number of motorcycles to the number of sedans is $3: 1$