The hexadecimal number system is a base-16 number system. This means that the system is based on grouping by 16, just as we group by tens in our decimal number system. Since the ones place, and all other places, can hold up to 15, but double digit numbers cannot appear in a single place, symbols are needed for the numbers 10 through 15. This is accomplished with the letters a through f, where a = 10, b = 11, c = 12, d = 13, e = 14, and f = 15. Counting in hexadecimal looks like this:

1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1a, 1b, 1c, 1d, 1e, 1f, 20, 21….

representing the decimal numbers 1 though 33.

For example, 1a = 1 group of 16 plus 10 ones = 16 + 10 = 26.

21 = 2 groups of 16 plus 1 one = 2 x 16 + 1 = 32 + 1 = 33.

So here is the Problem of the Week:

If only bad people understand hexadecimal, how many people understand hexadecimal?