The photos take up the entire frame with various colors instead of one solid one, so it is not likely for any of them to end up with a mismatch like this.
Naive attack, but it works well in my testing (ran it about 10 times, 100% success rate). If you have PIL installed, just run it through python and it'll grab an image and print whether it succeeded or failed to verify its solution.
(Adds a "Solve" link that moves the image rows into a solved position. Tested in Firefox 3.5.)
The stated problem is: “You have a 100 pound bag of potatoes. 99% of the bag is water weight. You leave the bag in the sun for a few hours. Now you bring it in and it is only 98% water weight, due to evaporation. What is the new total weight of the bag of potatoes?”
The first-reaction answer is that the bag now weighs 98 pounds. But originally the bag contained 1 lb of solid, 99 pounds of water. (Let's assume no other liquids than water). After evaporation, you still have 1 lb of solid, but it's now 2% of the total weight. For 1 pound of solid to equal 2% of total weight, the total weight has to be 50 pounds. That means the bag has only 49 pounds of water remaining. (That seems like a lot of evaporation for just a few hours in the sun.)
Seems to me that it would be 1.01%.
Per the problem statement, the 100-pound bag was initially 99% = 99 pounds of water. The non-water part (which we'll assume for simplicity was non-volatile solids) was therefore 100 pounds - 99 pounds = 1 pound. Solids don't evaporate, so even after evaporation, the 1 pound of solid matter remains. That 1 pound is now 2% = 1/50 of the weight, per above. The total weight after evaporation is therefore 50 pounds.
- Easier to defeat than OCR.
- Only 9 combinations, so random guessing works fine too.
- Visually impaired fail.