I liked this one for various reasons.
One train leaves Station A at 6 p.m. traveling at 40 miles per hour toward Station B. A second train leaves Station B at 7 p.m. traveling on parallel tracks at 50 m.p.h. toward Station A. The stations are 400 miles apart. When do the trains pass each other?
Entranced, perhaps, by those infamous hypothetical trains, many educators in recent years have incorporated more and more examples from the real world to teach abstract concepts. The idea is that making math more relevant makes it easier to learn.
That idea may be wrong.
1. The idea that when "everyone knows" something it's also true, was never very convincing to me. My reading of the story of humanity is that when "everyone knows", it may be true, and it may not - no more than that.
2. Kudos for the researchers who decided that accepted wisdom ought be questioned.
3. The honorable researchers seem to have discovered something I could have told them more than 40 years ago: That when faced by questions about trains in the night, at least some students are distracted from the maths into more important questions: Who was on the trains? Where were they going? What was the hurry? Why didn't they fly? Were they tense? Relaxed? Could they even have noticed the other train, or were they too involved in their own thoughts?