Perhaps it's shoddy coding on my part, but I got different result as well. It was actually raining for 111801 days out of a 1000000 Albert and Charlie said yes 81833 Betty and Charlie said yes 82640 Albert and Charlie said yes and it was true 49250 Betty and Charlie said yes and it was true 49631 Albert and Charlie said yes and it was a lie 16300 Betty and Charlie said yes and it was a lie 16681 It wasn't raining but everyone lied 32658 Times said 'yes' truthfully: 74377 Times said 'no' truthfully: 592897 Times said 'yes' and lied: 295302 Times said 'no' and lied: 37424 Betty Times said 'yes' truthfully: 74422 Times said 'no' truthfully: 592248 Times said 'yes' and lied: 295951 Times said 'no' and lied: 37379 Charlie Times said 'yes' truthfully: 74326 Times said 'no' truthfully: 592276 Times said 'yes' and lied: 295923 Times said 'no' and lied: 37475 I have used probabilities from the article. One out of three chance for a lie, one out of nine chance of rain being in Seattle. I can share my code if you would like to go for "maybe by spotting a problem with someone else's code I'll get some extra insight" type of exercise. Beware of sleepy Python though ;). Sample size for simulation: 1000000 In following the third person was saying the opposite: Albert and Betty said yes 82200 Albert and Betty said yes and it was true 49596 Albert and Betty said yes and it was a lie 16646 It was raining and everyone said true 32950 Albert