Prof. Giray Okten

Saturday, February 21, 2009

Week 3 - Problem 4

Rachel opened her math book and found that the sum of the facing pages was 243. What pages did she open to?


  1. She must have made a mistake. To get a sum of 243, she should have opened the book at pages 121 and 122, but those two pages are the opposite sides of a single sheet of paper in the book, so it's impossible to "open" a book right there!

  2. Silvia good comment- but our logic assumes the numbering is odd first, you could start with the numbering sequence 1-2, 21-22, 121-122.