Probability puzzle: How many balls in the bag?
Last week our village had a fête. One of the competitions on offer was to guess the number of balls in a bag. There were N balls in the bag, and they were numbered 1, 2, 3, …, N. To help competitors make a sensible guess, they were allowed to take out four balls and note the numbers on them.
When I took part, I pulled out balls numbered 24, 87, 14 and 35.
There is a prize for the person who guesses the correct number exactly. How many balls should I estimate are in the bag?
- Puzzle set by Michael Fletcher and published in the February 2022 issue of Significance.
- Try your hand at Michael's previous puzzle, "Classroom bingo", and read the solution in our latest issue (magazine subscription required).