This is actually a useful word problem, they only left out one part that would make it more practical: cars cost $50 to rent, vans cost $100 to rent. Now you've

This is actually a useful word problem, they only left out one part that would make it more practical: cars cost $50 to rent, vans cost $100 to rent. Now you've got a reason to prefer cars over vans. I (and in my experience most students feel the same) always liked learning better when it was about concrete problems and not just an abstract operation. If I'd had to learn programming without real-world applications, I wouldn't have bothered. I explain this by pointing out that physics has theoreticians and experimentalists. Seems to me that's about mental style. Also, it's easier to communicate an idea when you've got a physical metaphor.