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Brain Killers

After a long career as a mathematics teacher, a good friend recently donated his library (i.e. files and textbooks) to the students in my secondary mathematics methods class. While distributing the materials to the grateful students, I noticed one stapled packet labeled Brain Killers.

The packet was a typed collection of 314 odd-ball questions, many of them involving mathematics. The following are but a sample, one question for each day of this week:

  1. If the reflection of a clock in a mirror reads 8:45, what is the real time?
  2. There is a town in Virginia where 5% of all the people living in the town have unlisted phone numbers. If you selected 100 names at random from the town's phone directory, on average, how many of these people selected would have unlisted phone numbers?
  3. A train, 1 mile long, travels 1 mile a minute through a tunnel 1 mile long. How much time will it take for the train to pass completely through?
  4. Divide 30 by 1/2 and add 10. What is the answer?
  5. In digit format, write the number eleven thousand eleven hundred eleven.
  6. A cowboy rode into Dodge City on Friday, Stayed two days, then rode out of town on Friday. How come?
  7. Which is more: the number of seconds in 1,000 minutes or the number of feet in 100 miles?
Obviously, the set is dated, given Question #1. And, Question #6 may concern you for a while. But, as all of them include a "twist," they are considered Brain Killers!


Source: B.G. (Bellingham, WA)

Hint: No hint...just think clearly.


Solution Commentary: No answers...discuss your answers with others to reach agreement.