To determine which car has the greatest efficiency, we should consider the distance traveled per unit of fuel consumed (in kilometers per liter).
Here are the options analyzed:
-
1,200 kg car that travels 20 km per liter of fuel
- Efficiency: 20 km/l
-
1,200 kg car that travels 15 km per liter of fuel
- Efficiency: 15 km/l
-
900 kg car that travels 15 km per liter of fuel
- Efficiency: 15 km/l
-
900 kg car that travels 20 km per liter of fuel
- Efficiency: 20 km/l
From this analysis, the two cars with the highest distance per liter of fuel are the:
- 1,200 kg car (20 km/l)
- 900 kg car (20 km/l)
Since both the first and last options travel 20 km per liter, they are equally the most efficient among the given choices.
Thus, the answer is:
1,200 kg car that travels 20 km per liter of fuel (or the 900 kg car that travels 20 km per liter of fuel).