Here is the homework problem I gave to my PRIMES STEP students.
Puzzle. A man called his wife from the office to say that he would be home at around eight o’clock. He got in at two minutes past eight. His wife was extremely angry at this lateness. Why?
The expected answer is that she thought he would be home at 8 in the evening, while he arrived at 8 in the morning. However, my students had more ideas.
For example, one student extended the time frame.
- The man was one year late.
Another student found the words “got in” ambiguous.
- He didn’t get into his house two minutes past eight. He got into his car.
A student realized that the puzzle never directly stated why she got angry.
- The wife already got angry when he said he would be home around eight, as she needed him home earlier.
The students found alternative meanings to “called his wife from the office” and “minutes.”
- He had an office wife whom he called. But the wife at home was a different wife, and she was angry.
- “Two minutes past eight” could be a latitude.