Someone chooses a letter from the word ASTEROID, and your task is to ask questions until you can identify the chooser's letter. If the questions are of the form "which of the following tow words contains your letter?", two are sufficient for identification:
"Asteroid Prediction Tricks,"
Word Ways: Vol. 29
, Article 10.
Available at: http://digitalcommons.butler.edu/wordways/vol29/iss4/10