What is the total number of brake cylinders on these cars?

To determine the total number of brake cylinders on the cars in question, it's crucial to understand the standard configuration typically used in rail cars. Most rail cars are equipped with multiple brake cylinders to ensure effective braking across all wheels.

In this case, a typical setup for freight cars might consist of two brake cylinders per car—one for each truck or set of wheels. If there are two trucks per car and assuming there are two cars, that results in four brake cylinders in total (2 brake cylinders per car multiplied by 2 cars equals 4).

Therefore, the choice indicating four brake cylinders aligns with standard rail car design, confirming that this is the correct answer. Understanding the function of brake systems in rail operations is essential, as this ensures the safety and efficiency of train operations.