I had a theory and examined 100 various books from my book shelves. How many of them would you predict had an even number of numbered pages? The average of thirteen Facebook friends’ guesses was 78%. The true answer can be found below:
Sixty-two (or 62%) of the books had an even number of numbered pages, while 38% had an odd number. My theory had been that almost all of the books would be even-numbered, since every paper sheet has a front and back page, but I was mistaken.
A friend suggested: “If you check a thousand books, I’d bet the percentage is closer to fifty.”
However, according to this “Binomial Calculator,” if the true likelihood for odd or even page counts were equal, we should expect to find 62 or more even-numbered page counts out of 100 books slightly more than 1% of the time. If the true percentage were 56% or lower (that is to say, closer to 50% than 62%) the odds of finding 62 or more even-numbered page counts out of 100 would be less than 14%. Though the true percentage for all books may be closer to 50% than 62%, I have no reason to think that this is the case.