Calculating chances could be tough, with delicate adjustments in context giving fairly totally different outcomes. I used to be reminded of this lately after setting BrainTwister #10 for New Scientist readers, which was concerning the odds of seating two pairs of individuals adjacently in a row of twenty-two chairs.
A number of readers wrote to say my answer was fallacious. I had found out all of the attainable seating preparations and counted those that had the 2 teams adjoining. The readers, in the meantime, seated one pair first after which counted the methods of seating the second pair adjacently. Neither method was fallacious, relying on the way you…