Three closed boxes have either white marbles, black marbles or both, and they are labeled white, black and both. However, you’re told that each of the labels are wrong. You may reach into one of the boxes and pull out only one marble. Which box should you remove a marble from to determine the contents of all three boxes?
The one labeled both. Since you know it’s labeled incorrectly, it must have all black marbles or all white marbles. After you determine what it contains, you can identify the other two boxes by the process of elimination.
Nipples or teats. Cows have four of them, dogs usually have eight and a human (assuming that’s who’s reading this) has two. Cows milk standing up, dogs often lie down and women usually sit when breastfeeding.
This is a well known proverb that has had all of its vowels removed. In addition, the letters have been broken up into groups of four while maintaining their correct order.
The trick is that the word “dead” represents a number in hexadecimal. That number in base 10 is 57005, and adding one more to include yourself gives you: 57005 + 1 = 57006.
A similar problem can be found in L.A. Graham’s Ingenious Mathematical Problems and Methods with a range of 1 to 9, but the principle remains the same – the numbers with the smallest difference produce the largest product. You start out with the highest two digits, 7 and 6, then attach 5 and 4, putting the smaller of the two digits with the larger number, giving you 74 and 65. The next two highest digits are 3 and 2, giving you 742 and 653. Finally, you add the 1 to the lower number. Page 80 has the details of that solution.